Japanese Prime Minister Kishida Fumio arrived in the United States on Wednesday to join a NATO summit.
The summit has been underway in Washington since Tuesday.
Kishida is to meet with South Korean President Yoon Suk-yeol. They are expected to agree that the two countries will further improve ties.
The Japanese prime minister will take part in the summit on Thursday as the leader of a partner country of the alliance in the Indo-Pacific region, along with South Korea, Australia and New Zealand.
The participants are expected to confirm collaboration in supporting Ukraine and agree to step up cooperation in areas related to security, including measures against cyberattacks and fake information.
Through the meeting, Kishida wants to deepen ties with NATO members and other countries under the view that the security of Europe and that of Asia are inseparable, taking moves by Russia and China into consideration. Kishida believes stronger ties will also contribute to peace and stability around Japan.