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

Lawmakers from both sides of the aisle are filling up the House chamber, with the excitement of a joint meeting in the air as guests begin to take their seats and wait for the House Sergeant at Arms to announce the arrival of King Charles and Queen Camilla.

Hundreds of ticketed guests have crowded the House gallery, giving the event the feeling of a State of the Union address -- absent the president. Each member of Congress was given one ticket to give to a constituent or special guest.

Atop the speaker's rostrum, Vice President JD Vance and House Speaker Mike Johnson chatted while dignitaries filled the room.

Former Speaker Nancy Pelosi, wearing a lavender suit in the chamber, was also present when Queen Elizabeth gave her 1991 address to Congress.

-ABC News' John Parkinson, Rachel Scott and Lauren Peller

King Charles will soon deliver a joint address to Congress, a key moment of his four-day state visit. The last British royal to speak to a joint session of Congress was Queen Elizabeth II in 1991.

There will be plenty of pomp and show surrounding the king's speech, including a bipartisan escort committee that will trail him as he makes his way to the speaker's rostrum. Supreme Court justices, the diplomatic corps and president's Cabinet are all invited to attend as well. Vice President JD Vance is expected to sit alongside Speaker Mike Johnson atop the rostrum.

During the joint meeting, members of Congress may try to "hog the aisle" to get a moment gripping and grinning with the king.

Read more about the upcoming speech here.

-ABC News' John Parkinson and Lauren Peller

During their meeting at the White House, President Trump and King Charles exchanged gifts, according to the White House.

Trump gave Charles a copy of a 1785 letter written by John Adams to John Jay. In the letter, Adams describes being received by King George III as the first U.S. ambassador to Great Britain. Charles gave Trump a framed copy of the 1879 design plans for the Resolute Desk.

First lady Melania Trump gifted Queen Camilla with sterling silver teaspoons from Tiffany & Co. and some White House honey. On Monday, the Trumps showed the White House beehive to the royals. Queen Camilla gave Melania Trump a brooch from British designer Fiona Rae.

The king is now on Capitol Hill, where he will soon deliver an address to Congress. King Charles posed with House Speaker Mike Johnson for a photo as he entered the building.

The speaker and the king will soon walk through the Capitol for a meeting with the rest of congressional leadership, including Senate Majority Leader John Thune, Senate Minority Leader Chuck Schumer and House Minority Leader Hakeem Jeffries.