While Prime Minister Shinzo Abe and U.S. President Donald Trump engaged in golf diplomacy, their wives spent time Sunday learning about Japanese pearl cultivation in Tokyo's top luxury shopping district.

Akie Abe and Melania Trump visited the flagship Ginza store of accessories firm Mikimoto, which has long been an official jeweler to the Imperial family.

Kokichi Mikimoto, the brand's founder, created the world's first cultured pearl in 1893. The company now harvests the pearls offshore from an island in Mie Prefecture.

The pair warmly greeted each other at the store before speaking with two ama, traditionally trained female divers who collect pearl oysters and seafood without the use of scuba gear.

Trump posted on her official Twitter account that she and Akie had a "wonderful visit," enjoying "conversation over tea (and) the cultural presentation on the history of pearls."

Trump and first lady arrived at Yokota Air Base in western Tokyo soon after 1030 a.m. on Sunday for a three-day trip set to highlight the strength of the Japan-U.S. defense alliance in the face of the threat from North Korea and other regional challenges.

The wives spent some time together in Florida during Abe's visit to the United States in February, when they toured a Japanese garden.