The United States will not have normal ties with the Democratic People's Republic of Korea (DPRK) or relax its sanctions against the country until Pyongyang abandons nuclear arms, Secretary of State Hillary R. Clinton said in Washington on Wednesday.

In her policy address to the United States Institutes of Peace, Clinton reiterated the United States' willingness to have face-to-face talks with the DPRK on condition that the talks will lead to Pyongyang's return to the stalled six-party talks.

"North Korea's return to the negotiating table is not enough," Clinton said. "Current sanctions will not be relaxed until Pyongyang takes verifiable, irreversible steps toward complete denuclearization."

"Its (DPRK) leaders should be under no illusion that the United States will ever have normal, sanctions-free relations with a nuclear-armed North Korea," the top US diplomat added.

The DPRK conducted an underground nuclear test on May 25. It also boycotted the six-party talks on its nuclear program since April.

The six-party talks, involving the DPRK, the United States, China, the Republic of Korea, Japan and Russia, began in 2003.

The United States has been urging the DPRK to give up nuclear arms for years. Although it agrees to be open to have dialogue with Pyongyang, the Obama administration insists that Pyongyang must agree to return to the six-party talks.

Any of US bilateral contacts with the DPRK should lead to the resumption of six-party nuclear disarmament talks, Kurt Campbell, assistant secretary of state for East Asia, said at the Council on Foreign Relations on Tuesday.