- Democrats who signed the letter expressed "deep concern" that no ambassador has been nominated to South Korea
- The letter noted that the Senate has already confirmed 20 ambassadorships
The letter's 10 authors, including members of the Intelligence, Armed Services, and Foreign Relations committees, expressed "deep concern" that no ambassador had been nominated.
"As North Korea continues its illegal nuclear weapons program, commits blatant violations of international law, and makes threats to our country and allies, the confirmation of a US ambassador to the Republic of Korea must be prioritized," the letter said.
The letter noted that the Senate had already confirmed 20 ambassadorships, saying that the appointment of an ambassador to Seoul would "affirmatively convey to our (South Korean) allies that our relationship is valued in the same manner as these nations."
The authors also called for the appointment of an Assistant Secretary of State for East Asian and Pacific Affairs as well as the Assistant Secretary of Defense for Asian and Pacific Security Affairs, saying that permanent appointees would help ensure that recent sanctions aimed at curbing Pyongyang's nuclear and missile programs were properly enforces.
Currently both posts are being filled by senior civil servants in an acting capacity.
The letter's signatories included Sens. Elizabeth Warren, Mark Warner, Mazie Hirono, Dick Durbin and Tammy Duckworth, but did not include the ranking members of either the Senate Armed Services or Foreign Relations committees.
In the days leading up to the UN General Assembly in New York Trump has been actively engaged in diplomacy with countries in the region, conversations that have focused mainly on the threat posed by North Korea.
On Sunday, Trump spoke with his South Korean counterpart, Moon Jae-in, where they agreed to intensify economic and diplomatic pressure against North Korea's leader Kim Jong Un -- or "Rocket Man," as Trump nicknamed him
in a tweet -- over his nation's repeated nuclear and missile tests, according to a transcript of their conversation released by both presidential offices.
"President Trump and President Moon committed to continuing to take steps to strengthen deterrence and defense capabilities, and to maximize economic and diplomatic pressure on North Korea," the White House said in a statement.
Trump also spoke Monday with China's President Xi Jinping "to discuss North Korea's continued defiance of the international community and its efforts to destabilize Northeast Asia," according to a statement issued by the White House.