Donald Trump was “completely wrong” to cast doubt on the US election and encourage supporters to storm the Capitol, Boris Johnson has said.
The UK prime minister said he “unreservedly condemns” the US president’s actions.
Four people died after a pro-Trump mob stormed the building in a bid to overturn the election result.
Mr Trump had urged protesters to march on the Capitol after making false electoral fraud claims.
He later called on his supporters to “go home”, while continuing to make false claims – Twitter and Facebook later froze his accounts.
The president has now said there will be an “orderly transition” to Democrat Joe Biden, whose November election victory has now been certified by US lawmakers.
But he added that he continued to “totally disagree” with the outcome of the vote, repeating his unsubstantiated claims of electoral fraud.
On Wednesday night, Mr Johnson condemned the “disgraceful scenes” and called for a “peaceful and orderly transfer of power”.
But asked by the BBC’s political correspondent Alex Forsyth if President Trump was directly responsible, he said: “All my life America has stood for some very important things. An idea of freedom, an idea of democracy.
“As you say, in so far as he encouraged people to storm the Capitol, and in so far as the president has consistently cast doubt on the outcome of a free and fair election, I believe that was completely wrong.
“I believe what President Trump has been saying about that has been completely wrong and I unreservedly condemn encouraging people to behave in the disgraceful way that they did in the Capitol.”
The PM, speaking at a Downing Street briefing, then welcomed the confirmation of President Elect Joe Biden, saying “democracy has prevailed”.