Washington: World leaders and governments expressed shock, disbelief, and horror as unprecedented scenes unfolded in the heart of America after thousands of President Donald Trump's supporters stormed the US Capitol in an attempt to stop a peaceful transition of power.

The violence erupted after Trump supporters breached the Capitol and clashed with police on Wednesday, resulting in the death of four persons and interrupting a constitutional process to affirm President-elect Joe Biden's election victory. British Prime Minister Boris Johnson condemned the violence. "Disgraceful scenes in US Congress. The United States stands for democracy around the world and it is now vital that there should be a peaceful and orderly transfer of power," he tweeted. "The US rightly takes great pride in its democracy, and there can be no justification for these violent attempts to frustrate the lawful and proper transition of power," UK Foreign Secretary Dominic Raab said in a tweet. Prime Minister Narendra Modi said he was "distressed to see news about rioting and violence" in Washington. "Orderly and peaceful transfer of power must continue. The democratic process cannot be allowed to be subverted through unlawful protests," Modi said in a tweet. French President Emmanuel Macron in a video posted on his official Twitter account said: "We will not give in to the violence of a few who want to question democracy. We believe in democracy. What happened today in Washington is not American".

UN Secretary-General Antonio Guterres "is saddened by the events at the U.S. Capitol," UN spokesman Stephane Dujarric said, adding that "In such circumstances, it is important that political leaders impress on their followers the need to refrain from violence, as well as to respect democratic processes and the rule of law." Canadian Prime Minister Justin Trudeau tweeted that the scenes at the US Capitol were an "attack on democracy." "Canadians are deeply disturbed and saddened by the attack on democracy in the United States, our closest ally and neighbour. Violence will never succeed in overruling the will of the people. Democracy in the US must be upheld - and it will be," he said. German Foreign Minister Heiko Maas called on Trump supporters to "stop trampling on democracy". "The enemies of democracy will be happy to see these incredible pictures from Washington DC. Inflammatory words turn into violent acts," he tweeted.

"Shocking scenes in Washington, DC. The outcome of this democratic election must be respected," NATO chief Jens Stoltenberg tweeted. The EU's foreign policy chief condemned the "assault on US democracy, its institutions and the rule of law". "In the eyes of the world, American democracy tonight appears under siege. This is not America. The election results of 3 November must be fully respected," Joseph Borrell tweeted.