() President Donald Trump criticized South Korea on Monday, hours before he was set to welcome South Korean President Lee Jae Myung to the White House for talks on trade and defense.

It will mark the first in-person meeting for Trump and Lee, and a major agenda item is likely to be working through the details of a trade deal agreed upon earlier this summer.

Trump threatened a 25% tariff on South Korea, a country that has a trade surplus with the United States. When it comes to tariffs, Trump has proposed especially heavy duties on such countries.

The deal reached in July set tariffs on South Korean imports at 15% in exchange for investment in the U.S. economy, particularly in the areas of semiconductors, batteries and shipbuilding.

Defense will likely also be discussed, as Trump has pressed for more flexibility with security agreements and repeatedly suggested allies should pay more for U.S. troops.

Lee is expected to push back on the idea of a more flexible arrangement since U.S. troops in South Korea serve as a deterrent to North Korean aggression.

But the arrangement also serves U.S. interests, placing troops in the Indo-Pacific region and in close proximity to China, increasing readiness should a conflict break out in the region.

On social media Monday morning, Trump criticized the country now under Lee’s leadership.

“WHAT IS GOING ON IN SOUTH KOREA? Seems like a Purge or Revolution. We can’t have that and do business there. I am seeing the new President today at the White House. Thank you for your attention to this matter!!!” the president posted.

It’s not entirely clear to what exactly Trump was referring, but it appeared to be a reference to the investigation into former South Korean President Yoon Suk Yeol, who attempted to institute martial law in the country in December.

The statement came after Trump deployed National Guard troops in Washington, D.C., in an effort to crack down on crime in the nation’s capital. He has said he plans to deploy troops to other Democratic cities as well, starting with Chicago, over the objections of local leaders.

It’s not clear what the remarks could mean for the previously agreed-upon trade deal or the president’s relationship with Lee, who succeeded the conservative Yoon.