Democratic Sen. Tammy Duckworth last night criticized the president’s decision to no longer pursue former Bush adviser Victor D. Cha for U.S. ambassador to South Korea as a “troubling development” and a “setback for diplomacy.”

The Washington Post reported Tuesday Cha was dropped as a potential candidate for the ambassadorship after disagreements with the administration’s policy on North Korea were raised privately. Cha objected to the National Security Council’s consideration of a limited strike on North Korea meant to send a message without sparking a war, also known as a “bloody nose” strategy.

“This is yet another reason for every American to worry,” Duckworth, of Illinois, said in a statement to the Washington Examiner. “If this is report is true and we’ve truly reached a point where opposing unprovoked armed conflict is a disqualifier from serving as Ambassador … this represents a troubling development and setback for diplomacy.”

Cha also raised issues with the administration’s policies on trade, objecting to threats from the administration to leave a bilateral trade deal with South Korea over claims of unfairness to U.S. companies.

The Trump administration has now gone over a year without appointing a new ambassador to South Korea, a country that has been increasingly important over the past year as North Korea has ramped up development of its nuclear program.

“We have yet to nominate anyone for the post, but it is our intention to do so as soon as we can find the appropriate candidate,” said a White House official who spoke anonymously with the Washington Post.

Duckworth said that the failure of the Trump administration to nominate an ambassador to South Korea “sends a terrible message to our allies” and makes the jobs of U.S. officials stationed in Korea “much more dangerous.”

“Now more than ever, our diplomatic mission in South Korea needs permanent leadership in order to advance our nation’s interests,” Duckworth said.