(ATTN: UPDATES with context in paras 1, 5-8; CHANGES headline; TRIMS)
SEOUL, Oct. 3 (Yonhap) -- North Korea's chief nuclear negotiator on Thursday voiced "high expectations and optimism" over upcoming working-level talks with the U.S. as he left for Sweden for the meeting amid fresh tensions over Pyongyang's missile test.
"(We) are heading to working-level negotiations with the U.S," Kim Myong-gil told reporters at Beijing International Capital Airport. "As the U.S. side sent a new signal, I bear high expectations and optimism, and I am also optimistic about the results."
Earlier in the day, Kim and three other officials arrived in Beijing from Pyongyang for the high-stakes talks. The four were confirmed to have reserved tickets on an Air China flight bound for Stockholm.
North Korea's First Vice Foreign Minister Choe Son-hui said earlier this week that Pyongyang and Washington had agreed to hold preliminary contact on Friday before holding working-level negotiations on Saturday. She did not mention the venue for the talks.
The talks come just days after North Korea test-fired a new-type submarine-launched ballistic missile.
On Wednesday, South Korea's military said that the missile flew around 450 kilometers at a maximum altitude of about 910 kilometers.
The missile is presumed to have flown more than 2,000 kilometers, if it was fired at a normal angle, not "in vertical mode."
Wednesday's launch was North Korea's 11th weapons test so far this year and the first SLBM test since August 2016.
The talks will mark a resumption of the denuclearization process that has been stalled since February's summit between U.S. President Donald Trump and North Korean leader Kim Jong-un in Vietnam.
The summit fell apart as the two sides failed to iron out differences on the scope of Pyongyang's denuclearization steps and Washington's sanctions relief.
North Korea has urged Washington to come up with a new proposal that is acceptable to Pyongyang before the end of this year, ramping up its demand for sanctions relief and security guarantees in exchange for denuclearization steps.
In January, nuclear envoys of the two Koreas and the U.S. held talks in Sweden ahead of the Trump-Kim summit.
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