TOKYO (Kyodo) -- Japanese Foreign Minister Takeshi Iwaya embarked Sunday for the United States to attend President-elect Donald Trump's inauguration the following day, aiming to hold talks with key figures in the incoming U.S. administration during his five-day trip.

During his stay in Washington, Iwaya is eying a meeting with Sen. Marco Rubio, the nominee for U.S. secretary of state awaiting Senate confirmation, to lay the groundwork for a summit between Trump and Japanese Prime Minister Shigeru Ishiba.

Japanese government sources have said Ishiba is planning a visit to the United States, the Asian nation's close security ally, no earlier than the first half of February for a meeting with Trump.

The United States reinforced its alliance with Japan in the past four years under U.S. President Joe Biden, and the two countries bolstered cooperation under multilateral collaborative frameworks, including trilateral arrangements with South Korea and the Philippines.

But uncertainty is now causing concern as Trump is expected to take an "America First" unilateralist approach to foreign affairs, as the Republican did during his first four-year presidential stint from 2017.

Iwaya said he will be the first Japanese foreign minister to attend a U.S. presidential inauguration. Traditionally, Japan's ambassador to the United States has represented the country.

Representatives of Japan, the United States, Australia and India, which compose the Quad grouping, are arranging a meeting on Tuesday in the United States, according to the sources.