North Korea's chief nuclear negotiator arrived in Stockholm Thursday to resume working-level denuclearization negotiations with the United States this weekend.

Kim Myong-gil and his delegation arrived at Stockholm Arlanda Airport around 5:40 p.m. on a flight from Beijing. They left the airport shortly after through the VIP hall instead of the main arrivals gate.

The US chief negotiator, Stephen Biegun, is also expected to head to the Swedish capital soon. North Korea said earlier that the two sides will have preliminary contact Friday before holding working-level discussions on Saturday.

It will be the first round of formal negotiations since a February summit between US President Donald Trump and North Korean leader Kim Jong-un in Vietnam ended without any agreement.

The two sides are expected to focus on finding common ground between US demands for the North's complete and verified denuclearization and Pyongyang's demands for sanctions relief and security guarantees.

The talks also come only days after North Korea test-fired what it said was a submarine-launched ballistic missile off its east coast on Wednesday.

In Washington, Trump indicated the negotiations will still go ahead as planned.

"We'll see," he told reporters when asked if the North had gone too far this time with the SLBM launch. "They want to talk, and we'll be talking to them soon. We'll see."

The North Korean delegation in Sweden was seen getting into several black cars at the airport, with the press trailing behind in an attempt to determine their destination.

The officials are presumed to have entered the North Korean Embassy in Stockholm after reporters spotted several cars pulling into the compound.

Before departing Beijing, Kim Myong-gil told reporters he was optimistic about the outcome of the talks.

"As the US side sent a new signal, I bear high expectations and optimism," he said without elaborating on what the new signal was.

Last month Trump suggested that a "new method" could be good for the stalled negotiations. (Yonhap)