U.S. President Barack Obama said on Thursday that his administration is trying to "keep a door open" for the Democratic People's Republic of Korea (DPRK)'s return to the six-party talks which was designed to make the settlement of nuclear issues on the Korean peninsula.

U.S. President Barack Obama speaks during a news conference in the Brady Press Briefing Room of the White House in Washington June 23, 2009.(Xinhua/Reuters Photo)

In his exclusive interview with The Associated Press, Obama insisted that the DPRK give up its nuclear weapon programs.

That is "the only way Pyongyang is going to improve its economy and join the world community," Obama was quoted as saying.

Also on Thursday, State Department spokesman Ian Kelly urged Pyongyang to return to international nuclear disarmament talks.

"North Korean knows exactly what it has to do. ...They need to cut out these kinds of provocative actions and return to denuclearization talks," said Kelly, referring to South Korea's reports that the DPRK test-fired four short-range missiles earlier in the day.

The six-party talks, involving the DPRK, the United States, China, South Korea, Japan and Russia, was first held in Beijing, China in August 2003, and has made tangible progress in the following years, including the demolition by the DPRK of the cooling tower at its Yongbyon nuclear complex in June 2008.

However, the disarmament talks suspended since December 2008 due to sharp differences between the United States and the DPRK over, among others, the verification of the disable nuclear facilities.

Editor: Olivia