U.S. President Donald Trump says he wants to meet North Korean leader Kim Jong Un later this year, but Pyongyang has responded coolly, signaling it could impose tough conditions on any new talks despite Trump’s claims that the two leaders have an “excellent” relationship.

Earlier this week, Trump abruptly scaled back joint U.S. military exercises with South Korea, calling the drills “hostile” toward North Korea. On Wednesday, he said he expected to meet Kim later this year as he seeks to revive stalled diplomacy with Pyongyang.

Trump is eager to restart negotiations with North Korea and secure a foreign policy breakthrough, according to a person briefed on discussions between U.S. and South Korean officials.

The outreach comes as Trump faces limited prospects for ending the nearly six-month war with Iran. It also comes despite North Korea’s growing military support for Russia, including the deployment of troops and the supply of equipment and missiles for Moscow’s war in Ukraine.

South Korea has been privately receptive to Trump’s strategy, although officials in Seoul still have doubts about reducing joint military exercises with the United States, the source said.