The United States was trying to gauge whether North Korea is willing to abandon its nuclear weapons in exchange for better relations during a second day of rare exploratory talks on Friday.

North Korean Vice Foreign Minister Kim Kye Gwan arrived more than a half-hour later than expected for the meeting at the U.S. mission to the United Nations. Walking past a crowd of cameramen, photographers and reporters, Kim was greeted by Clifford Hart, the U.S. special envoy to formal six-party talks on North Korean De-Nuclearization.

U.S. Ambassador Stephen Bosworth, the Obama administration's top envoy on North Korean affairs, arrived earlier, telling reporters only that "the talks continue."

Under so-called six-party talks, the United States, China, Japan, South Korea and Russia have been negotiating since 2003 with Pyongyang to persuade North Korea to dismantle its nuclear weapons programs. Pyongyang pulled out of the six-party talks in April 2009 after being censured for launching a long-range missile, vowing never to return.

This week's high-level meetings have raised hopes of a breakthrough in resuming the disarmament negotiations. The State Department said the five hours of discussions held Thursday were "serious and business-like."

Pyongyang has recently expressed a willingness to rejoin the talks. But Seoul and Washington have insisted that inter-Korean ties must improve first following two attacks that killed 50 South Koreans last year.

This week's discussions aim to build on last week's surprise talks between nuclear negotiators from North and South Korea on the sidelines of a regional security gathering in Indonesia, the first such meeting since disarmament talks were last held in December 2008. The arms talks collapsed shortly afterward.

The U.S. hopes to use this week's meetings to determine if North Korea is ready to fulfill its commitments under a 2005 joint declaration requiring the North to abandon all nuclear weapons programs and allow the return of international weapons inspectors. In exchange, Pyongyang would get better relations with its Asian neighbors, energy assistance, and a pledge from Washington that its troops won't attack the North.

Secretary of State Hillary Rodham Clinton invited the North Korean vice foreign minister to New York after what U.S. officials described as a constructive meeting. But she said the U.S. wouldn't reward the North for just returning to the table or promising to uphold old agreements.

Scott Snyder, a Washington-based Koreas specialist for the Council on Foreign Relations, said there is much skepticism about the sincerity of the North Koreans, who have conducted a second nuclear test and revealed a uranium enrichment facility that could give it another way to make nuclear bombs since the last talks in 2008.

Nevertheless, Snyder told AP, the talks are "significant, in that it is the first time in a while to exchange views directly."

Former U.S. ambassador to the U.N. John Bolton, now at the conservative American Enterprise Institute, was pessimistic.

"There is simply no evidence and there hasn't been for 10 years that the North Koreans are really prepared to give up their nuclear weapons program," Bolton told the AP.