North Korea has asked the United States to decide on a format for talks to replace the Korean War armistice with a peace treaty.

North Korea’s Ambassador to Russia Kim Yong-jae told Russia’s state-run RIA Novosti news agency on Wednesday that Pyongyang has asked the U.S. to decide on a format for talks on a peace treaty, adding that such discussions could take place within the six-way nuclear talks or separately.

Kim’s statement suggests that U.S. and North Korean officials touched on the issue of peace treaty talks when they met for bilateral discussions in Pyongyang last month.

Kim added that it remains uncertain whether South Korea would be open to holding the talks on adopting a peace treaty.