The United States and South Korea have reached a cost-sharing agreement that will include a “meaningful increase” in payments for U.S. troops on the Korean Peninsula and launched annual joint military exercises, in a partial reset between the two nations.

Negotiations over how to share the costs of the military alliance came to an impasse in March 2020 when the Trump administration demanded that Seoul increase its contribution fivefold. Officials have not provided details on the new deal, which is being finalized.

The nine-day joint military exercise set to begin this week will mostly be conducted as computer simulations, rather than in the field, because of the coronavirus pandemic, according to a statement from South Korea’s Joint Chiefs of Staff.

The moves mark a shift from the previous administration, as President Biden seeks to show that the United States is committed to its allies and military defense agreements.

As president, Donald Trump sharply criticized allies for not paying enough toward the cost of U.S. military defense in their countries, including on the Korean Peninsula, where about 28,500 U.S. troops are stationed. His demands led to increased tensions and sparked concerns in South Korea that the United States could reduce its troop presence if it did not meet the request.

Trump also questioned the need for large-scale military exercises each spring with South Korea, calling them expensive and complaining that the United States was not being “reimbursed.” The drills were reduced in size and scope, and incorporated more computer simulations, as Trump tried to engage with North Korea leader Kim Jong Un.

North Korea views the exercises as preparation for an attack, while U.S. and South Korean officials say they are defensive in nature.

With another year of reduced exercises, experts have raised concerns about the prolonged lack of field trainings.

“I don’t care what the military says in terms of workarounds, it’s not helping readiness,” said Victor D. Cha, an expert on Korean relations who served in the administration of President George W. Bush. “Militaries have to exercise to be ready. So, I’m sure there is some erosion of readiness because they have not been able to exercise.”

U.S. military officials have sought to cast their commitment to South Korea as enduring.

“The United States’ security commitment to the Republic of Korea is unshakable, consistent with the Mutual Defense Treaty, and U.S. forces in Korea are specifically postured to ‘fight tonight,’ if needed,” said Army Lt. Col. Martin Meiners, a Pentagon spokesman.

During the presidential campaign, Biden pledged to take a more measured approach toward U.S. relations with South Korea.

“As President, I’ll stand with South Korea, strengthening our alliance to safeguard peace in East Asia and beyond, rather than extorting Seoul with reckless threats to remove our troops,” he wrote in an October 2020 column for South Korea’s Yonhap News Agency.

A State Department spokesman said Sunday that the cost-sharing agreement “reflects the Biden-Harris administration’s commitment to reinvigorating and modernizing our democratic alliances around the world to advance our shared security and prosperity.”

In a statement, the South Korean Ministry of Foreign Affairs said the two sides had decided to “resolve the gap in the agreement that has lasted for more than a year through prompt signing of the agreement, and will contribute to strengthening” the alliance between the countries.

The countries considered a roughly 13 percent increase to Seoul’s payments, or about $1 billion per year, according to two officials, who spoke prior to the Sunday announcement on the condition of anonymity to discuss ongoing negotiations. Trump had rejected that proposed amount in 2019, instead demanding up to $5 billion.

“These negotiations have always been contentious between Washington and Seoul in every administration, but Trump’s election defeat has helped a lot this time,” said Duyeon Kim, a Korea expert at the Center for a New American Security. “Concluding them will remove a big irritant and show that the allies are restoring a part of the alliance, but it’s comparatively easier to resolve, because Seoul already had an offer on the table.”

Cha said that the Biden administration is walking a line in its relationship with South Korea, seeking greater payments while also showing that the alliance is strong.

But there was room for compromise after Trump made “extreme demands that were not really realistic,” Cha said.

The deal with South Korea is crucial to U.S. efforts to counter China’s rise with a coalition of like-minded allies, said James Kim, a research fellow at the Asan Institute for Policy Studies in Seoul.

If the Americans doubled down on Trump’s pressure on Seoul to pay more, “that could actually push the Koreans further away from them and toward Beijing if they’re not careful,” James Kim said. “Biden wants to forge a better relationship with the allies.”

The joint military exercises send a message to the South Korean public and North Korea that the Biden administration is committed to its alliances with South Korea and Japan and defending them, Duyeon Kim said.

“Halting joint drills will only embolden Pyongyang, and it would be like dropping your shield before a drawn sword,” she said.

But the exercises this year will mostly involve computer simulations, rather than tens of thousands of troops training in the field with aircraft, ships and other equipment. In addition to addressing concerns about the coronavirus, the setup also lowers their profile as South Korean President Moon Jae-in seeks to maintain peaceful relations with North Korea.

Army Col. Lee Peters, a U.S. military spokesman in South Korea, said ahead of the announcements that it is U.S. policy not to comment “on planned or executed training,” and called it something that professional militaries do to “maintain readiness, proficiency, credibility, and trust.”

The training, he said in an email, “ensures we maintain a robust combined defense posture” and enhance the ability of the U.S. and South Korean militaries to work together.

North Korea has not signaled how it plans to engage with the United States, but the exercises could prompt action, experts say.

In a speech to the party Congress in January, the North Korean leader called on Washington to end the joint exercises and other alliance activities on the peninsula.

“We will have to see how Pyongyang protests the drills, especially when it’s preoccupied with domestic challenges. It would be a big mistake to provoke the Biden administration with a weapons or satellite test, especially before his team and policy are in place,” Duyeon Kim said. “Whatever action or inaction Pyongyang takes will foreshadow what the U.S.-North Korea and inter-Korean relationships will look like in the foreseeable future.”

John Hudson in Washington and Simon Denyer in Tokyo contributed to this report.