U.S. and North Korean diplomats concluded on Friday their two-day talks in New York that both sides called "constructive."

North Korean First Vice Foreign Minister Kim Kye-Gwan was invited to New York for "exploratory talks" with U.S. Special Representative for North Korea Policy Stephen Bosworth after North Korea and South Korea agreed on July 22 to revive the stalled six-party talks on the North's nuclear program.

No details of the talks, the first since 2009, have been announced. The U.S. Department of State issued a statement saying that the negotiations "were to explore the willingness of North Korea to take concrete and irreversible steps toward denuclearization."

The discussions were "constructive and business-like," the statement said.

Kim also described the talks as "useful and constructive." Pyongyang is set to continue contacts with the United States, he told journalists in New York.

The North Korean government's support of the six-party talks would open the path for Pyongyang towards better relations with the United States and greater regional stability, the State Department said in the statement.

The United States will consult closely with South Korea and other partners in the six-party talks (Russia, China and Japan) before deciding on next steps to resume the process, the statement said.

The six-party talks on Pyongyang's nuclear ambitions came to a halt in April 2009 when North Korea walked out of negotiations to protest the United Nations' condemnation of its missile tests.

North Korea is banned from conducting nuclear or ballistic missile tests under UN Resolution 1718, adopted after Pyongyang's first nuclear test on October 9, 2006.

However, the country carried out a second nuclear test on May 25, 2009, followed by a series of short-range missile launches, and has threatened to build up its nuclear arsenal to counter what it calls hostile U.S. policies.