Russian president Vladimir Putin has described the Prince of Wales's reported comparison of him with Adolf Hitler as "unacceptable" and "wrong" and said that remarks of this kind are "not what monarchs do".
Mr Putin's response came just days after the Prince was reported to have made the remark in a private conversation during his visit to Canada.
The Russian president was asked for his response by Press Association chief executive Clive Marshall during an interview with the world's leading news agencies in St Petersburg.
Mr Putin said: "It reminds me of a good proverb: 'You are angry. That means you are wrong.'"
In a direct personal message to the Prince, he added: "Give my words to Prince Charles. He has been to our country more than once, i f he made such a comparison, it is unacceptable and I am sure he understands that as a man of manners."
Mr Putin added: "I met him personally, as well as other members of the Royal Family. This is not what monarchs do.
"But over the past few years we have seen so much, nothing surprises me any longer."
Charles's comments were reportedly made to Canadian museum volunteer Marianne Ferguson, 78, after she told him how her Jewish family fled the Nazi occupation of Danzig at the outset of the Second World War, and appeared to draw a parallel with Russia's annexation of the Ukrainian peninsula of Crimea in March.
The Russian president made clear that he would not allow the disapproval of prominent international figures such as the Prince of Wales to influence his actions in the current crisis in Ukraine.
"I will be guided not by what they say about me anywhere," he said. "I will only be guided by the interests of the Russian people, and I hope our colleagues in Great Britain will keep that in mind and will always remember that when finding solutions to any issues, we are always guided by international law and its norms."
Britain has led international calls for sanctions against Russia in response to its actions in Crimea, and last week Prime Minister David Cameron warned that the UK may have to prepare for "a very different long-term relationship with Russia" if Moscow failed to take action to de-escalate the crisis.
But Mr Putin indicated that he did not regard the current differences as the start of a long-lasting rift in UK-Russian relations, and said he anticipated a return to "good co-operation" if the UK decided to be guided by its own "national interests".
Mr Putin said: "Only if we respect international law will we be able to find solutions to the most difficult issues.
"Should our British partners be guided by their national interests - like I do - and not by other reasons, I am sure this will soon become a thing of the past and we will be able to continue good co-operation like back in the days, and maybe even reach some new heights and can start thinking about what is to be done in the future in order to make our co-operation more efficient."
A spokeswoman for the Prince of Wales declined to comment on Mr Putin's criticism.
Charles's remark has sparked particular anger in Russia because of the country's pride in its contribution to the defeat of Nazism in the Second World War, which cost the lives of an estimated 26 million Soviet citizens, including almost 8 million members of the military.
Mr Putin did not refer directly to Russia's wartime sacrifices in his response to the Prince's remark. But he pointedly mentioned them earlier when discussing the upcoming 70th anniversary commemorations of the D-Day landings in Normandy, which they are both due to attend.
"During the Second World War, we were allies and we were fighting together against Nazism," said Mr Putin.
"As you know very well, the peoples of the Soviet Union and the people of Russia sacrificed a lot to win the war and achieve our joint victory over Nazism.
"That is why it is quite natural that we are going to have a meeting in Normandy and we are going to pay tribute to our coalition partners, to the British, the Americans and the French."
Mr Putin's 90-minute televised interview at his official residence of Constantine Palace at Strelna came at the end of an international economic forum in nearby St Petersburg at which he struck a conciliatory note on Ukraine, indicating that he will recognise the victor of tomorrow's presidential election in the former Soviet state.
Today, he repeated that promise, telling senior executives and correspondents from 12 news agencies: "We will treat any choice of the Ukrainian people with due respect."
He added: "We are going to treat the choice of the Ukrainian people with due respect and we are going to work with the authorities that are going to be shaped based on the elections."
However, he made clear that he continues to regard former president Viktor Yanukovych, ousted in February after months of protests, as Ukraine's legitimate leader.
Ukraine's constitution allowed presidents to be removed on grounds of incapacity, impeachment or resignation, he said, adding: "Look at the Ukrainian constitution. Read the words. We are adults. We can read."
Mr Putin said that he would have preferred to see a referendum staged on a new constitution before any presidential election, as envisaged in an agreement between the regime and opposition shortly before Yanukovych's removal in what he termed an "anti-constitutional coup d'etat".
Asked whether the Ukraine crisis was pushing the world towards a new Cold War, Mr Putin said: "I wouldn't like to think that it is the beginning of a new Cold War, because no-one is interested in that and I think it will not happen."
Mr Putin said Russia was ready to take part in dialogue and seek solutions using the tools of international diplomacy, but said "those tools must be used not to serve the interests of just one country but to look for compromise which would be acceptable to all the participants in this process".
And he added: "There are some red lines that we can't cross and Ukraine and the Crimea is such a red line."
The overthrow of Yanukovych, following months of street protests against his decision to tear up a proposed agreement which would have tightened Ukraine's economic links with the EU, created a threat to Russia's national interests, he said.
"Some events that took place in Ukraine are threatening our interests, first of all security interests," he said. "The prospect of Ukraine accessing Nato, which could be followed by not only the accession but also placing the military complexes in Ukraine territory and in Crimea. If that happened, for Russia de facto (it) would have serious geopolitical consequences.
"De facto, it would be squeezed out from the Black Sea region, from a region where Russia fought for a presence for many centuries."
He asked: "Where are the guarantees that Ukraine will not access Nato tomorrow?... Where is the guarantee that in the Crimea there would not be a missile defence system, had not the Crimean people voted for joining Russia? There were no guarantees."
He said that Russia had acted "in full compliance with international law" in recognising the right of the people of Crimea to self-determination after they voted in a referendum to join the Russian Federation.
Mr Putin said sanctions imposed by the EU and US on Russia in response to what they regard as the annexation of Crimea were "counter-productive and not based on any fair treatment of the existing problems".
He said the sanctions were dictated by the desire to impose conditions on Russia "which do not correspond to international law or mutual interests or to Russian interests".
Asked whether he feared Russian isolation as a result of further international sanctions on trade and the economy, Mr Putin said: "I believe that the isolation of such a country as Russia is immaterial, it is impossible.
"I believe we could do a lot of damage to each other and when there is a difficult situation in the world economy, who needs this damage?"
He suggested that the determination of EU leaders to impose sanctions on Russia was not supported by all of their peoples: "I am not sure that a lot of citizens of the European states would support their leaders. I believe that in Europe many people would support our position and in the end people are the source of power.
"As far as the consequences are concerned, they would be negative for everyone. They would lead the European, Russian and world economy to such turbulence that is not in the interests of anyone. And there could be damage if crazy measures were taken, but I don't see any grounds for that."
Mr Putin rejected suggestions that Moscow was putting unfair economic pressure on the interim authorities in Kiev by raising the price of energy supplies, insisting that this involved simply removing a discount which had previously been offered to Ukraine, which he said had not been paying its bills since last July.
"How can anyone reproach us?" he asked. "We have been so generous. We have shown a true spirit of partnership when it comes to dealing with our Ukrainian friends."
Asked about concerns that Russia may reduce exports of gas to Europe in the wake of the massive £240 billion deal to supply China which he sealed in Beijing earlier this week, Mr Putin said: "Do you think that we would stop supplying gas to Europe? That would go against our own interests. That would be suicidal."
The Russian president dismissed suggestions that he was trying to recreate the old Soviet Union by forging a customs union with former territories of the USSR, such as Belarus and Kazakhstan.
"It is a mistake to believe so," said Mr Putin. "It is not only irrelevant to reality, it is a tool in the information war. They are trying to stick this label on us, they are trying to label us and say we are trying to restore the empire, the Soviet Union, and exercise influence in that territory. It is not true."
The aim of the proposed Eurasian Union was to take advantage of the shared infrastructure which the countries had inherited from their shared predecessor state, for the economic well-being of their peoples, he said.
Mr Putin said that the EU's refusal to enter talks on co-operation with the proposed customs union was "astonishing" and said he would press ahead with the publication of a treaty on the Eurasian Union in the coming days.