WASHINGTON, United States (AFP) —The United States warned Tuesday that North Korea’s invitation to South Korea’s Winter Olympics must not undermine international efforts to isolate Kim Jong-Un’s regime.

The US State Department gave a cautious welcome to the talks between Seoul and Pyongyang that set the stage for the North to take part in the Pyeongchang Winter Games next month.

But the welcome was hedged with concern that the slight thaw in ties between the historic foes would represent an opening for Kim’s regime to escape its diplomatic isolation.

“The United States remains in close consultations with ROK officials, who will ensure North Korean participation in the Winter Olympics does not violate the sanctions imposed by the UN Security Council over North Korea’s unlawful nuclear and ballistic missile programs,” spokeswoman Heather Nauert said.

As President Donald Trump “said to ROK President Moon on January 4, the United States is committed to a safe and successful Winter Olympic Games, and the United States will send a high-level presidential delegation to the Games,” she said.

“During the same conversation, the two leaders also agreed to continue the campaign of maximum pressure on North Korea toward the goal of complete and verifiable denuclearization of the Korean peninsula.”

Nauert had no comment on the news that Seoul and Pyongyang had also agreed to hold military talks and to restore a military hotline closed since February 2016.