OTTAWA, Ontario (AP) — King Charles III will outline new Prime Minister Mark Carney's government priorities in a speech in the Canadian Parliament on Tuesday. It's widely viewed as a show of support in the face of annexation threats by U.S. President Donald Trump.

Trump’s repeated suggestion that the U.S. annex Canada prompted Prime Minister Carney to invite Charles to give the speech from the throne. The king is the head of state in Canada, which is a member of the British Commonwealth of former colonies.

Carney said in a statement the visit speaks to the “vitality of our constitutional monarchy and our distinct identity.”

It is rare for the monarch to deliver what’s called the speech from the throne in Canada. Charles’ mother, Queen Elizabeth II, did it twice in her 70-year reign, the last time in 1977.

The speech is not written by the king or his U.K. advisers as Charles serves as a nonpartisan head of state. He will read what is put before him by Canada’s government.

Carney, the new prime minister and a former head of the Bank of England, and Canada’s first Indigenous governor general, Mary Simon, the king’s representative in Canada, met with the king on Monday.

Canadians are largely indifferent to the monarchy, but Carney has been eager to show the differences between Canada and the United States. The king’s visit clearly underscores Canada’s sovereignty, he said.

Carney won the job of prime minister by promising to confront the increased aggression shown by Trump.

The new U.S. ambassador to Canada, Pete Hoekstra, said sending messages to the U.S. isn’t necessary and Canadians should move on from the 51st state talk, telling the Canadian Broadcasting Corporation that if there’s a message to be sent there are easier ways to do that, such as calling him or calling the president.

“There are different ways to ‘send a message’ and a phone call is only of them," said Daniel Beland, a political science professor at McGill University. "The King would normally add his own short introductory remarks and observers will be listening to them very carefully with the issue of Canada’s sovereignty in mind.”

A horse-drawn carriage will take the king and queen to the Senate of Canada Building for the speech. It will accompanied by 28 horses, 14 before and 14 after. He will receive the Royal Salute from the 100-person guard of honor from the 3rd Battalion, Royal Canadian Regiment before entering the chamber for his speech.

The king will return to the U.K. after the speech and a visit to Canada’s National War Memorial.

Justin Vovk, a Canadian royal historian, said the king’s visit reminds him of when Queen Elizabeth opened the Parliament in Grenada, a member of the commonwealth, in 1985.

A U.S.-led force invaded the islands in October 1983 without consulting the British government following the killing of Grenada’s Marxist prime minister, Maurice Bishop.