South Korea’s new president, Lee Jae Myung, will face a pivotal moment on Monday when he meets US President Donald Trump in Washington for their first summit, as the countries’ decades-old alliance strains to confront rapid geopolitical changes.

Much is riding on the meeting for Lee, who took office in June after a snap election called after his conservative predecessor - feted in Washington for his hard line on North Korea - was removed for attempting to impose martial law.

South Korea’s economy relies heavily on the US, Washington underwrites the country’s security with troops and nuclear deterrence, and Lee hopes to chart a balanced path of cooperating with the United States while not antagonizing top trade partner China.

South Korea has long come under targeted criticism from Trump, who has called it a “money machine” that takes advantage of American military protection.

Lee will seek to make a good impression, connect personally with Trump, and above all, avoid any unpleasant surprises, analysts said.

“For Lee, a no-news summit I think would be good,” said Victor Cha of the Centre for Strategic and International Studies.

However, Cha said what Trump’s aides produce for him to talk about at the meeting may be completely different from what President Trump wants to talk about.

Under heavy pressure from Trump’s administration, South Korean negotiators secured a last-minute deal last month to avoid the harshest of tariffs but must still hammer out details of billions of dollars in promised investments.

South Korean officials say they hope such working-level trade negotiations will largely be left for other meetings.

“There are many major topics in the security field,” Lee’s top policy aide, Kim Yong-beom, said on Wednesday. “Our position is that trade was already finalised last time. We hope that specific implementation plans for trade won’t be included in the summit at all, or at least should be kept simple if discussed.”

Several top officials, including the foreign minister, rushed to Washington over the weekend to try to iron out final details.

Lee, who arrived in Washington on Sunday, will highlight some of South Korea’s expected investments when he visits a shipyard in Philadelphia owned by the country’s Hanwha Group after the summit. Cooperation to help the ailing US shipbuilding sector is part of the broad tariff agreement reached between the countries.

Trump is expected to pressure Lee to commit to more spending on defense, including potentially billions of dollars more toward the upkeep of 28,500 American troops stationed in South Korea.

Wi Sung-lac, Lee’s top security adviser, said South Korea was in talks with Washington on Seoul’s higher defense spending, taking as a reference NATO’s agreement on a big new defense spending target. Wi added that the government was also looking into a plan for the purchase of American weapons.

Duyeon Kim, from the Center for a New American Security, said to avoid any public splits, the leaders should focus on reaffirming long-standing alliance principles and broadly agreeing to expand cooperation in all areas.

While focusing on increasing military spending, Lee will likely seek to avoid conversations about a potential reduction of US troops or using them for a wider range of operations, or details on modernizing the alliance, she said.

“They should leave those topics for working-level officials to hash out,” Kim said. “Ambition could backfire.”

Lee said it is difficult for Seoul to accept the demand by the United States to adopt “flexibility” of operating the US military now stationed in South Korea, Yonhap news agency reported on Monday.

Trump and Lee may also discuss efforts to persuade North Korea to freeze and eventually abandon its nuclear weapons programme. Both leaders support engaging Pyongyang, and Lee has called for a phased approach to denuclearization.

But North Korea has rejected both American and South Korean overtures so far, and said it will never give up its nuclear arsenal. Leader Kim Jong Un has said the US and South Korea remain hostile to his country and he supervised test firing of new air defence systems over the weekend.

Before Lee meets Trump, the South Korean leader travelled to Tokyo to meet Japanese Prime Minister Shigeru Ishiba on Saturday to underscore the importance of cooperation between South Korea, Japan and the US

Lee and Ishiba discussed relations with Washington and US tariff issues and the Japanese leader shared his experience with Trump, which for Seoul was useful information before Lee’s first meeting with Trump, said Wi, the South Korean security adviser.