WASHINGTON -- President Yoon Suk Yeol arrived in Washington on Wednesday to attend a North Atlantic Treaty Organization summit with a strong message against North Korea's military cooperation with Russia amid the prolonged war in Ukraine.

South Korea was invited to the NATO summit for the third consecutive year as one of the Indo-Pacific partners, alongside Japan, Australia and New Zealand.

During his two-day stay, Yoon is expected to have a series of bilateral meetings with leaders from over 10 countries, including Japan, Britain, Germany, Canada, Finland, Norway, the Netherlands, Sweden and the Czech Republic.

Later in the day, Yoon and first lady Kim Keon Hee are scheduled to join a welcome dinner hosted by U.S. President Joe Biden and first lady Jill Biden.

On Thursday, the president will have a four-way meeting with his counterparts from Japan, Australia and New Zealand and attend a session of the NATO allies and partners to boost cooperation between the transatlantic military alliance and the Indo-Pacific.

He will also deliver a speech at the NATO Public Forum, an event co-organized by five think tanks in Europe and the United States.

Stakes are higher for this year's summit as South Korea has said it would consider supplying arms to Ukraine after Russia signed a mutual defense treaty with North Korea last month.

Russian President Vladimir Putin warned it would be a "big mistake" if Seoul sent arms to Ukraine, while President Yoon insisted Seoul's decision would depend on Moscow's approach to its military cooperation with Pyongyang.

Seoul officials are concerned that Moscow could provide technological assistance to Pyongyang's nuclear and missile program in return for its munitions and weapons support for Russia's war in Ukraine.