U.S. President Donald Trump, his predecessor Barack Obama and British Prime Minister Theresa May have not been invited to the wedding of Prince Harry and Meghan Markle on May 19, royal and British government sources said on Tuesday.

Neither has Prime Minister Justin Trudeau.

"While the prime minister and Sophie Grégoire Trudeau will not be attending the wedding, we congratulate Prince Harry and Ms. Markle and wish them the best," Trudeau's office said in a statement Tuesday.

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Governor General Julie Payette's office also sent out a statement saying she will not be attending. "She will send personal congratulations and wishes to the new couple on the occasion of their wedding," the statement said.

Harry, grandson of Queen Elizabeth and younger brother of Prince William, will marry Markle, an American actress best known for her role in the TV series Suits, at St George's Chapel in Windsor Castle.

Neither Prime Minister Justin Trudeau nor U.S. President Donald Trump was invited to next month's royal wedding. (Jonathan Ernst/Reuters)

"It has been decided that an official list of political leaders — both U.K. and international — is not required for Prince Harry and Ms. Markle's wedding," said a spokesperson for Kensington Palace, the official residence of William and Harry.

"Her Majesty's Government was consulted on this decision, which was taken by the Royal Household," the spokesperson said. "Her Majesty's Government" is the official name of the British government.

British PM not attending

A Kensington Palace source confirmed the Obamas would not be attending and said the wedding guests would be people who have an existing direct relationship with the groom or the bride or with both. That excludes Trump.

There had been some speculation that the Obamas might be invited due to the personal rapport between the former president and Harry, but it would have been diplomatically awkward to invite the Obamas and not the Trumps.

Although the royal family is expected to steer well clear of politics, Britain's delicate constitutional balance means that its members have to consult discreetly with the government to ensure their public actions comply with foreign policy.

Former U.S. president Barack Obama and Prince Harry have a close personal rapport, as is evident in this photo of them watching a wheelchair basketball event during the Invictus Games in Toronto last September. (Mark Blinch/Reuters)

A British government source confirmed May would not be attending and said there had been no expectation that she would.

The government source noted that the wedding venue was significantly smaller than Westminster Abbey, where Harry's

older brother William wed Kate Middleton in 2011 in the presence of then-prime minister David Cameron and other politicians and diplomats.

Obama, who was then in office, was not invited to that wedding and the United States was represented by its ambassador to the United Kingdom.

Kensington Palace on Tuesday named some of the 1,200 people, chosen because of their strong leadership and community service, who have been invited into the grounds of Windsor Castle on the wedding day to join the celebrations.

The list included people who ran a wide variety of charity organizations as well as veterans from the armed forces who have suffered life-changing injuries.