Trump on verge of 2nd impeachment

US President Donald Trump criticized Democrats in the House of Representatives on Tuesday for seeking to impeach him for inciting the riot at the Capitol last week, but cracks emerged in the president's party, with several Republicans now turning against him before a historic second impeachment.

The House started to debate impeaching Trump on Wednesday because of the Capitol riot, according to media reports.

Representatives were expected to vote on his impeachment after the debate.

Trump said the impeachment is a "continuation of the greatest witch hunt in the history of politics" and that it was "causing tremendous anger". He made the remarks to reporters on Tuesday before boarding Air Force One at Joint Base Andrews for a trip to the US-Mexico border wall near Alamo, Texas.

They were his first public comments since Jan 6, when the Capitol was overrun after Trump gave a speech near the White House in which he urged thousands of backers to march on Congress to pressure legislators to overturn President-elect Joe Biden's victory.

In Alamo, Trump dismissed Democrats' calls for Vice-President Mike Pence and Trump's Cabinet to declare him unfit for office and remove him from power using the 25th Amendment of the Constitution.

Asked by reporters whether he held any "personal responsibility" for the riot at the Capitol, Trump said that "people thought that what I said was totally appropriate".

On Tuesday evening, the House approved a resolution that set a 24-hour deadline for Pence to invoke the 25th Amendment, though Pence had already said in a letter to House Speaker Nancy Pelosi that he would not employ it, and that he didn't think it was "in the best interest of our nation or consistent with our Constitution".

The resolution, passed 223-205 almost entirely along party lines, urged him to "declare what is obvious to a horrified Nation: That the President is unable to successfully discharge the duties and powers of his office".

With Pence's refusal to invoke the amendment, the House is set on Wednesday to vote on its second impeachment of Trump.

Some Republican lawmakers said they would vote to impeach Trump on Wednesday, cleaving the Republican leadership, and the party itself.

Liz Cheney of Wyoming, the No 3 Republican leader in the House, said in a statement, "The president of the United States summoned this mob, assembled the mob, and lit the flame of this attack.

"There has never been a greater betrayal by a president of the United States of his office and his oath to the Constitution."

The New York Times reported on Tuesday that "according to people familiar with his thinking", Mitch McConnell of Kentucky, the Republican leader in the Senate, has told associates that he believes Trump committed impeachable offenses and that he is pleased that Democrats are moving to impeach him, believing that it will make it easier to purge him from the party.

Chen Yingqun in Beijing and May Zhou in Houston contributed to this story.

Xinhua contributed to this story.