SEOUL (Reuters) - South Korea's President Yoon Suk Yeol was visiting Ukraine for the first time on Saturday for talks with President Volodymyr Zelenskiy, Yonhap news agency said, citing the South Korean presidential office.

The surprise trip came after Yoon attended a NATO summit in Lithuania and visited Poland this week, where he expressed solidarity with Ukraine and explored ways to support its fight against Russia's invasion.

A U.S. ally and rising arms exporter, South Korea has faced renewed pressure to provide weapons to Ukraine, which Yoon's administration has resisted in favour of humanitarian and financial aid, wary of Russia's influence over North Korea.

(Reporting by Joyce Lee; Editing by William Mallard)