South Korea's President Lee Jae Myung faces a pivotal foreign policy test barely two months after taking office, with back-to-back summits in Tokyo and Washington that reflect the wider struggle of U.S. allies to navigate Donald Trump’s unilateral push to redefine postwar orders on trade, security and alliances.

A day after confirming his August 25 summit with Trump, Lee’s office announced he will visit Japan on August 23-24 to meet Prime Minister Shigeru Ishiba, a rare diplomatic setup that underscores how Trump is drawing closer two often-feuding neighbours with deep-rooted historical grievances.

The Associated Press explains Lee's back-to-back summits in Tokyo and Washington.