King Charles III visit live updates: Loud applause after Charles' comments on checks to executive power

The House chamber remained at capacity throughout the king’s remarks. It was not apparent that any lawmakers walked out of the address in protest and there were no protests or outbursts.

Several times, Charles was met with bipartisan praise -- including when he spoke of checks and balances on executive power and when he called for peace in Ukraine.

The king departed the chamber and shook hands with military officials, retired Supreme Court Justice Stephen Breyer, lawmakers on both sides of the aisle -- including Senate leaders John Thune and Chuck Schumer -- and other rank-and-file House members.

-ABC News' Lauren Peller

Amid tensions between the U.S. and U.K. over the war in Iran and other diplomatic issues, King Charles urged cooperation between the two countries.

"The story of the United Kingdom and the United States is, at its heart, a story of reconciliation, renewal and remarkable partnership," he said. "From the bitter divisions of 250 years ago, we forged a friendship that has grown into one of the most consequential alliances in human history.

"I pray with all my heart that our alliance will continue to defend our shared values with our partners in Europe and the commonwealth and across the world, and that we ignore the clarion calls to become ever more inward-looking," he said.

King Charles emphasized the importance of the NATO alliance as he spoke about how the U.K. answered the call after the terror attacks against the U.S. on Sept. 11, 2001.

"Today, Mr. Speaker, that same unyielding resolve is needed for the defense of Ukraine and her most courageous people," Charles said. "It is needed in order to secure a truly just and lasting peace from the depths of the Atlantic to the disastrously melting icecaps of the Arctic."

"The commitment and expertise of the United States Armed Forces and its allies lie at the heart of NATO, pledged to each other's defense, protecting our citizens and interests, keeping North Americans and Europeans safe from our common adversaries," he said.

His comments come amid Trump's criticism of NATO after several allied countries refused to back the U.S. war in Iran.

It's something that we don't see often in a divided Congress: a packed chamber, full of laughter, unity and standing ovations.

The laughter in the chamber is echoing off the walls. The king has had to stop a few times to allow for more laughter and applause.

Democrats and Republicans are listening attentively -- more than they do with a president even from their own party.

-ABC News' Rachel Scott