U.S. academics and former senior officials met with North Korea's chief nuclear negotiator in Singapore on Sunday to get a feel for each other's positions amid a yearslong standoff over the North's nuclear weapons buildup.

Leon Sigal, director of the Northeast Asia Cooperative Security Project at the Social Science Research Council, a U.S.-based nonprofit, told reporters that the meeting will cover the North's nuclear missile programs. He said "it's two ways of taking each other's temperature."

The U.S. and North Korea have no formal diplomatic ties, but former U.S. officials occasionally meet the North's diplomats in a bid to settle the impasse over Pyongyang's pursuit of a long-range nuclear-armed missile that could hit the U.S. mainland.

North Korea's team was led by Ri Yong Ho, the chief negotiator for six-party denuclearization talks.

North Korea has indicated willingness to rejoin the long-stalled talks, but has balked at U.S. demands it first take concrete steps to show it remains committed to the denuclearization goal.

Earlier this month, North Korea told the United States that it is willing to impose a temporary moratorium on its nuclear tests if Washington scraps planned military drills with South Korea this year. Washington called the linking of the military drills with a possible nuclear test "an implicit threat," but said it was open to dialogue with North Korea.

Pyongyang is thought to have a handful of crude nuclear bombs and has conducted three nuclear tests since 2006. But experts are divided on how far the opaque government has come in the technology needed to miniaturize a warhead.

Asked whether the two sides would also discuss recent hacking attacks linked to the comedy flick "The Interview," Sigal said: "I don't think we will get into that very much."

The U.S. blames the North for crippling cyberattacks on Sony Entertainment, which released the movie depicting the assassination of North Korean leader Kim Jong Un, and subsequently imposed new sanctions on the country. Pyongyang has denied responsibility for the cyberattacks and accused the U.S. of engineering recent Internet disruptions in the country.

Others taking part in the Singapore talks, which go on until Monday, include former U.S. special envoy for North Korea Stephen Bosworth, former deputy nuclear negotiator Joseph DeTrani and Tony Namkung, former deputy director at Berkeley's Institute for East Asian Studies.