(CNN) - Britain's Prince Charles has agreed to meet with US President Donald Trump during his controversial state visit to the UK next month, CNN has learned, in a move that sets up the prospect of a diplomatically awkward exchange over climate change.
Trump and Charles, heir to the UK throne, are expected to meet for afternoon tea at Clarence House, the official residence of the Prince and his wife Camilla, Duchess of Cornwall.
While a state visit guarantees an audience with Queen Elizabeth II, visiting leaders don't automatically get a one-on-one with Charles.
The prince's office declined to comment publicly on the meeting, or the agenda. But given Charles' passionate and lifelong environmentalism, and Trump's well-known climate-change skepticism, it seems inconceivable that the issue would not be discussed.
Charles warned against "potentially catastrophic global warming" in a speech during a tour of the Caribbean in March. "We demand the world's decision-makers take responsibility and solve this crisis," he said. The Trump administration, by contrast, has been accused of deprioritizing the issue, withdrawing from the Paris climate accords in 2017.
The most likely date for the Trump-Charles encounter is June 3, the first day of the president's visit. According to tradition, a state banquet, hosted by Queen Elizabeth, will take place on the first evening.
It's unclear whether the meeting came at the behest of Downing Street, which steers the itinerary of state visits in consultation with the Palace, the prince's office, or the White House.
Downing Street declined to comment, saying it was a matter for the Palace. CNN has sought comment from the White House.
A political prince
In the past, Charles has come under fire for testing the boundaries of the custom that senior British royals stay out of politics. He has often written to government ministers on subjects close to his heart -- like the environment and modern architecture.
But in a recent BBC documentary celebrating his 70th birthday, the prince promised not to meddle in matters of public debate once he takes on the role of the monarch.
Trump's meeting with Charles will be the first since being elected. They previously met during a 2005 tour of the US by Charles and Camilla.
British Prime Minister Theresa May first invited Trump for a full state visit shortly after he took office in 2016. The invitation prompted 1.8 million to sign a petition in protest.
Trump's first trip to the UK as president, in July 2018, was subsequently styled as a working visit. It nevertheless prompted huge protests in central London, including a 20-foot "Trump baby" blimp that flew over the UK Parliament -- all with the blessing of London's Mayor Sadiq Khan.
The two men have verbally sparred frequently and last week Khan said he didn't see a reason to roll out the red carpet. But Khan doesn't get much of a say in the protocols of a presidential visit, and this time around Trump will enjoy the full trappings of a state occasion.