Japan's Emperor and Empress arrived in London on Wednesday to attend British Queen Elizabeth II's Diamond Jubilee celebration on Friday.

Akihito and his wife Michiko are scheduled to attend a luncheon hosted by the Queen at Windsor Castle as part of the Diamond Jubilee celebration events.

The 78-year-old Emperor underwent heart bypass surgery in February but was cleared by doctors for this trip. It is their first overseas visit since 2009 when they flew to Canada and Hawaii.

"I am very happy to have an opportunity to express my congratulations to Her Majesty, who is still performing well her duty as the Queen," the Emperor said at Haneda airport in Tokyo, according to Kyodo News.