Britain's King Charles III (right) speaks with Britain's Prime Minister Rishi Sunak at Buckingham Palace, in central London, on Feb 21, 2024 for their first in-person audience since the King's diagnosis with cancer. (PHOTO / AFP)

LONDON - Britain's King Charles said during a meeting with Prime Minister Rishi Sunak on Wednesday he had been reduced to tears by messages of good will following his cancer diagnosis.

The palace announced earlier this month that Charles, 75, had been diagnosed with a form of cancer, less than 18 months into his reign.

"I've had so many wonderful messages and cards ... it's reduced me to tears most of the time," Charles said during his weekly audience with Sunak.

"Everyone is behind you," Sunak responded.

ALSO READ: King Charles gives thanks for support after cancer diagnosis

The monarch holds weekly audiences alone with the prime minister, although occasionally cameras have been allowed to capture the start of the meetings.

Britain's King Charles III (left) and Queen Camilla leave after attending a Sunday church service at St Mary Magdalene Church in Sandringham, Norfolk, England, on Feb 18, 2024. (PHOTO / AP)

Wednesday's meeting is the first formal in-person audience Charles has held with Sunak since it was revealed that he was suffering from an unspecified form of cancer.

Buckingham Palace has said the king will continue to carry out state business and his official paperwork while he undergoes cancer treatment.

Sunak began the exchange by telling Charles it was wonderful to see him looking so well.

READ MORE: King Charles seen in public for the first time since cancer diagnosis

"Well it's all done by mirrors," Charles joked.