The United Kingdom will host Donald Trump for a state visit this year, but King Charles and the US president won’t be able to meet informally over the summer due to their busy diaries, CNN understands.

According to BBC, Buckingham Palace has confirmed that King Charles sent Trump a formal letter called a "Manu Regia" inviting him to the U.K. last week, which was delivered to Washington via representatives from the British Embassy.

King Charles will welcome President Donald Trump at Windsor Castle for his second state visit to the UK in September. The monarch, 76, extended an unprecedented invitation to the commander in chief and First Lady Melania Trump earlier this year following his election win,