One person has been shot at the U.S. Capitol as dozens of supporters of President Donald Trump stormed the building and violently clashed with police.

That's according to a person familiar with the matter who spoke to The Associated Press on Wednesday on condition of anonymity amid a chaotic situation.

The exact circumstances surrounding the shooting were unclear. The person said the victim had been taken to a hospital. Their condition was not known.

The shooting came as dozens of Trump supporters breached security perimeters and entered the U.S. Capitol as Congress was meeting, expected to vote and affirm Joe Biden's presidential win. Trump has riled up his supporters by falsely claiming widespread voter fraud to explain his loss.

President Donald Trump is encouraging supporters occupying the U.S. Capitol to ``remain peaceful,'' but he is not calling for them to disperse.

As he faced growing pressure from allies to condemn the violence Wednesday afternoon, Trump tweeted, ``No violence!'' adding: ``Remember, WE are the Party of Law & Order - respect the Law and our great men and women in Blue.''

But Trump did not ask supporters to vacate the area as the unrest continued.

Trump had appeared earlier at a rally and had urged his supporters to march to the Capitol _ at one point even suggesting he would join them. He is upset that he lost the presidential election to Democrat Joe Biden and has falsely claimed voter fraud to explain it away.

He also urged his supporters to ``get rid of the weak Congress people'' _ presumably through primary challenges _ saying, ``get the weak ones get out; this is the time for strength.''

A Defense Department official says Washington, D.C., has requested an additional 200 National Guard members as supporters of President Donald Trump violently clash with law enforcement at the Capitol.

That request is currently under review at the Pentagon to determine how the Guard can respond to support law enforcement.

According to officials, the Guard members have a very specific mission that does not include putting military at the Capitol. Instead, the Guard must be used to backfill law enforcement outside the Capitol complex, freeing up more law enforcement to respond to the Capitol.

Officials said the request for more National Guard has not been rejected.

Trump had urged his supporters to come to Washington to protest Congress' formal approval of President-elect Joe Biden's win. Several Republican lawmakers backed his calls, despite there being no evidence of fraud or wrongdoing in the election.