US President Donald Trump, facing impeachment on a charge of "incitement of insurrection" on Tuesday disavowed responsibility for his supporters' violent invasion of the US Capitol last week and said his remarks before the siege were appropriate.The Republican president told reporters his speech before Wednesday's assault - in which he urged supporters to march on the Capitol and fight - had been analyzed by unnamed others, who he said believed it was "totally appropriate." "If you read my speech ... what I said was totally appropriate," he told reporters at Joint Base Andrews when asked about any personal responsibility he had regarding the Jan. 6 attack when his supporters stormed the Capitol with members of Congress and his own Vice President Mike Pence inside."They've analyzed my speech and my words and my final paragraph, my final sentence and everybody ... thought it was totally appropriate," he said before heading to Alamo, Texas to visit and sign his signature wall on the border with Mexico.Democrats in the US House of Representatives plan to impeach Trump on Wednesday unless he steps down or is removed before then, which would make him the only US president ever to be impeached twice.Trump's remarks on Tuesday were his first in public since Wednesday, although he released a video on Thursday in which he condemned the violence but did not concede the election.Trump did not answer a shouted question before leaving the White House about whether he was responsible for the violence at the Capitol, which led to the deaths of six people.House Republican Leader Kevin McCarthy told Republicans on Monday that Trump had acknowledged during a phone call that he bears "some responsibility" for the siege."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," McCarthy told Republicans during a 2-1/2-hour conversation, according to a source who took part in the call.SECURITY CONCERNSWashington remains on high alert ahead of Biden's inauguration, which had already been scaled back dramatically because of the raging COVID-19 pandemic.The National Guard was authorized on Monday to send in up to 15,000 troops, and tourists were barred from the Washington Monument due to threats of more violence from Trump supporters.The FBI has warned that armed protests are being planned in the US and state capitals ahead of the inauguration, according to a federal law enforcement official.Rep. Conor Lamb, a Pennsylvania Democrat, told CNN that thousands of armed pro-Donald Trump extremists are plotting to surround the US Capitol ahead of President-elect Joe Biden's inauguration. He was among those briefed on Monday on a series of new threats against lawmakers and the Capitol itself."They were talking about 4,000 armed 'patriots' to surround the Capitol and prevent any Democrat from going in," he told CNN. "They have published rules of engagement, meaning when you shoot and when you don't. So this is an organized group that has a plan. They are committed to doing what they're doing because I think in their minds, you know, they are patriots and they're talking about 1776 and so this is now a contest of wills."Two members of the Capitol Police have been suspended in connection with last week's attack and 10 to 15 officers are under investigation, Democratic US Representative Tim Ryan told an online news conference.Senate Democratic leader Chuck Schumer said US officials should place people who were inside the Capitol building on the federal "no fly" list. “We cannot allow these same insurrectionists to get on a plane and cause more violence and more damage," he said at a news briefing.The Washington Post reported on Tuesday that a day before rioters stormed Congress, an FBI office in Virginia issued an explicit internal warning that extremists were preparing to travel to Washington to commit violence and “war.” The newspaper cited an internal document that contradicts a senior official’s declaration the bureau had no intelligence indicating anyone at last week’s pro-Trump protest planned to do harm.“As of 5 January 2021, FBI Norfolk received information indicating calls for violence in response to ‘unlawful lockdowns’ to begin on 6 January 2021 in Washington. DC,” the document reviewed by the Washington Post says. “An online thread discussed specific calls for violence to include stating ‘Be ready to fight.’”One suspended officer took a selfie with a protester, while another wore a Trump-supporting hat and started directing protesters around, said Ryan, who chairs a House subcommittee looking into how Capitol security was breached.The lawmakers who drafted the impeachment charge say they have locked in the support of at least 214 of the chamber's 222 Democrats, indicating strong odds of passage.Democratic Representative Diana DeGette said some Republicans had privately expressed support for impeachment.Omri Nahmias contributed to this report.