'Can't bear this bloody thing': Leaky pen irks King Charles | Watch

Britain's Camilla, Queen Consort (R) watches as Britain's King Charles III signs the visitors' book.

Britain's King Charles vented his frustration at a leaky pen on Tuesday during a signing ceremony in Northern Ireland, the second time in recent days he has shown visible irritation during such proceedings.

Charles, visiting Northern Ireland as part of a tour of the United Kingdom to lead mourning for his mother Queen Elizabeth, was greeted by cheering crowds and welcoming speeches, before delivering his own pledge to the region.

Shortly after, when signing a visitors' book in front of cameras at Hillsborough Castle near Belfast, Charles reacted in frustration when a pen he was using leaked on his hand.

"Oh god I hate this (pen)!" Charles said, standing up and handing the pen to his wife and Queen Consort Camilla.

King Charles is angry with the pen today.