WASHINGTON - The United States on Monday once again urged the Democratic People's Republic of Korea (DPRK) to take steps toward denuclearization with a view to resuming "credible" negotiations.

State Department spokeswoman Jennifer Psaki repeated the US position as the DPRK reportedly fired a day earlier five short-range projectiles, presumed to be tactical missiles.

"I would reiterate our call on North Korea (DPRK) to immediately cease all threats, reduce tensions and take the steps toward denuclearization needed to resume credible negotiations," she said at a daily news briefing.

She noted, however, that Washington could not confirm Pyongyang's latest missile firings as reported by South Korea's Yonhap News Agency, which came just two days after the DPRK fired off ship-to-ship missiles in waters off Wonsan area.

The DPRK made a fresh call last month for an unconditional resumption of the six-party talks over its nuclear program at the conclusion of a two-day unofficial meeting with former US special representative for DPRK policy Stephen Bosworth in Singapore.

Washington rejected the offer, as it had conditioned more six-party talks on Pyongyang's concrete steps toward denuclearization.

The six-party talks, which also involve Russia, China and Japan, were initiated in Beijing in August 2003 but have been stalled since December 2008. The DPRK dropped out of the talks in April 2009.