Yuko Kishida. (Kyodo)

The wife of Prime Minister Fumio Kishida is planning to visit the United State as early as next month to meet with first lady Jill Biden at the White House, a Japanese government source said Wednesday.

Yuko Kishida, who has yet to meet the first lady despite their husbands having met, has received an invitation from the U.S. side, the source said. It is unusual for a Japanese prime minister's wife to visit the United States alone.

When President Joe Biden visited Tokyo in May last year, he said he wanted Yuko Kishida to come to the United States to meet his wife, other sources said.

The prime minister visited Washington in January this year for the first time after taking office in 2021. But his wife did not accompany him, apparently taking into consideration the fact that the first lady had just had surgery to remove cancerous skin lesions.