Washington:<Text>

South Korean Foreign Minister Cho Hyun arrived in Washington early Friday, three days ahead of a meeting between Presidents Lee Jae Myung and Donald Trump, a source said, amid speculation that his earlier-than-expected arrival may suggest the need to further fine-tune the summit agenda. Cho came to the U.S. capital via Atlanta, the source said.

According to Yonhap News Agency, Cho was initially expected to accompany Lee during the president's trip to Tokyo for talks with Japanese Prime Minister Shigeru Ishiba this weekend. However, he skipped it to visit the U.S. capital, raising questions over whether there are differences between Seoul and Washington over trade or alliance issues.

Cho could meet Secretary of State Marco Rubio as early as Friday to make final summit preparations, observers said. A Seoul official has stated that his visit ahead of Lee's arrival was intended to make "scrupulous" and "thorough" preparations.

The summit is expected to be a crucial moment for the South Korea-U.S. alliance as Lee and Trump might discuss a set of consequential issues that could affect the future trajectory of the longstanding security partnership. Chief among the issues is the two countries' joint effort for "alliance modernization" that analysts suggest could include readjusting the size, composition, role, and operational scope of the 28,500-strong U.S. Forces Korea to focus on deterring the "pacing threat" from an increasingly assertive China.

Discussions on alliance modernization might also involve Trump's call for allies to increase their defense spending and undertake greater security burdens.