WASHINGTON (REUTERS) - US President Donald Trump acknowledged he bears "some responsibility" for an assault on the US Capitol last week, Republican congressional leader Kevin McCarthy told party lawmakers on Monday (Jan 11), according to two people familiar with Mr McCarthy's briefing.

Mr McCarthy, who said he believed Mr Trump was responsible for the violence, shared details of a phone conversation he had with Mr Trump during an emotional 2-1/2-hour long call with Republicans, many of whom remain divided over the attack, the sources said.

Thousands of Trump supporters stormed the seat of Congress last Wednesday, forcing lawmakers who were certifying Democratic President-elect Joe Biden's election victory into hiding in an attack that left five people dead.

The violence occurred shortly after Mr Trump urged supporters to march on the Capitol during a rally where he repeated false claims that the Nov 3 election was "rigged" against him.

Mr Trump initially ignored demands that he condemn the attack, repeating his false claims about election fraud and referring to the supporters involved in the siege of Congress as "very special".

A day later, he described the violence as "a heinous attack" and pledged to work towards a smooth transfer of power, although he did not concede defeat in the election.

"I have been very clear to the president. He bears responsibility for his words and actions," Mr McCarthy told fellow Republicans on Monday, according to one of the sources.

"I asked him personally today if he holds responsibility for what happened, if he feels bad about what happened. He told me he does have some responsibility for what happened."

Mr McCarthy said he appealed to Mr Trump to call Mr Biden.

"I'm asking you personally. Call Joe Biden. For the sake of this nation."