LIMA, Peru —  President Biden is gathering with South Korean President Yoon Suk-yeol and Japanese Prime Minister Shigeru Ishiba for talks Friday amid heightened concerns about North Korea’s growing military partnership with Russia and Pyongyang’s stepped-up cadence of ballistic missile tests.

The meeting on the sidelines of the Asia-Pacific Economic Cooperation summit in Peru comes as North Korea has deployed thousands of troops to Russia to help Moscow try to claw back land in the Kursk border region that Ukraine seized earlier this year.

North Korean leader Kim Jong Un also ordered a series of ballistic missile tests in the lead-up to this month’s U.S. election and is claiming progress on efforts to build capability to strike the U.S. mainland.

White House officials are concerned that Pyongyang could be dialed up for more provocative action ahead of President-elect Donald Trump’s inauguration and the early days of his administration.

“I do not think we can count on a period of quiet with the DPRK,” said White House national security advisor Jake Sullivan, using the initials for North Korea’s formal name. “The possibility of a seventh nuclear test remains ever present and something we’re vigilant for. The transitions have historically been time periods when the DPRK has taken provocative actions both before and after the transition from one president to a new president.”

Biden is on a six-day visit to Latin America for the final major international summits of his presidency, following up APEC with a gathering in Brazil of leaders from the Group of 20 top economies. He’s likely to face questions from world leaders about the incoming administration as they turn their attention to what Donald Trump’s return to the White House will mean for them.

Biden took part in an informal meeting with other APEC leaders Friday, walking in as Peru President Dina Boluarte was delivering her welcoming remarks. Biden, who is also meeting later Friday with Boluarte, shook hands with leaders from Thailand and Vietnam.

With the growing North Korea-Russia relationship top of mind, the U.S., Japanese and South Korean leaders planned to discuss the North’s soldiers deploying to Russia and ensure their three countries are acting in a “coordinated way,” Sullivan said.

The introduction of North Korean troops to the Russia-Ukraine conflict comes as Moscow has seen a favorable shift in momentum in the grinding war on its neighbor. Trump has signaled that he could push Ukraine to agree to give up some land seized by Russia to find an end to the conflict.

Up to 12,000 North Korean troops have been sent to Russia, according to U.S., South Korean and Ukrainian assessments.

U.S. and South Korean intelligence officials say North Korea also has provided Russia with significant amounts of munitions. South Korea’s spy agency said last month that North Korea had sent more than 13,000 containers of artillery, missiles and other conventional arms to Russia since August 2023 to replenish its dwindling weapons stockpiles.

The meeting will be the first face-to-face engagement between Biden and Ishiba, who took office on Oct. 1, replacing his unpopular predecessor Fumio Kishida.

Ishiba pledged to pursue a military buildup plan under a 2022 security strategy adopted by his predecessor, which calls for a counterstrike capability with long-range cruise missiles, a break from its self-defense-only principle. Ishiba said he will seek to improve cooperation between Japanese and U.S. troops.

The trilateral talks are a follow-up on a partnership launched at a historic 2023 meeting between Biden, Yoon and Kishida at the U.S. presidential retreat at Camp David, Md.

Biden nudged Japan and South Korea to put aside years of historic animosity and strengthen economic and security ties as the countries confront the threat from North Korea as well as increasing military assertiveness by China in the Pacific.

The three countries signed a pledge agreeing to consult, share information and align their messaging with each other in the face of a threat or crisis.

Sullivan said the Biden administration is working to ensure the three-country cooperation is “an enduring feature of American policy.” He expects it would continue under Trump, noting its bipartisan support, but acknowledged it was up to the incoming president’s team.

Both Yoon and Ishiba already have reached out to Trump and are aiming to keep their countries’ relationships with the incoming administration on steady footing amid the heightened tensions.

South Korea’s presidential office says Yoon also would meet Chinese leader Xi Jinping on Friday to discuss economic cooperation and cultural exchanges as well as the security situation on the Korean Peninsula.

North Korea fired a barrage of short-range ballistic missiles into the sea just hours before election day in the United States.

Those launches came days after Kim supervised a flight test of the country’s newest intercontinental ballistic missile designed to be able to reach the U.S. mainland. In response, the United States flew a long-range B-1B bomber in a trilateral drill with South Korea and Japan on Sunday in a show of force.

Madhani writes for the Associated Press. AP writer Rebecca Santana in Washington contributed to this report.