The United States welcomes South Korean President Yoon Suk Yeol's recent trip to Ukraine, a state department spokesperson said Monday, calling on all other countries to join in supporting the war-torn country.

Yoon made a surprise trip to Ukraine on Saturday, during which he met with Ukranian President Volodymyr Zelenskyy and promised to provide a comprehensive package of security, humanitarian and reconstruction assistance, dubbed the "Ukraine Peace and Solidarity Initiative."

"We welcome the visit. We welcomed the president's expression of support," state department Press Secretary Matthew Miller said of Yoon's trip to Ukraine when asked in a press briefing.

"We always think it's important when other foreign leaders can make the trip to Ukraine to speak firsthand with President Zelenskyy and other members of the Ukrainian government, to see the destruction that has been inflicted on that country by Russia," added Miller.

Yoon's trip to Ukraine came at the end of his two-nation trip that took him to Lithuania for a North Atlantic Treaty Organization summit and to Poland on an official visit.

"We encourage every country in the world to join us in supporting Ukraine," Miller told the press briefing.

The Yoon-Zelenskyy meeting marked the second of its kind following their first meeting on the sidelines of a Group of Seven summit in Hiroshima, Japan in May.

Yoon had promised additional non-lethal assistance and $100 million worth of humanitarian assistance to Ukraine after his first meeting with the Ukrainian president in May.

He said Seoul will provide non-lethal military supplies and an additional $50 million worth of humanitarian aid under the Ukraine Peace and Solidarity Initiative. (Yonhap)