Talks for a peace treaty on the Korean Peninsula and lifting of sanctions on the Democratic People 's Republic of Korea (DPRK) should be based on achieving progress in the process of the DPRK's denuclearization, Wi Sung-lac, Special Representative for Korean Peninsula Peace and Security Affairs, said on Sunday.

The remark came after Wi, also Seoul's top negotiator in the six party talks over DPRK's nuclear program, returned from a four- day trip in the United States.

Wi told South Korea's Yonhap News Agency that the nuclear negotiations and talks for a peace treaty "do not clash with each other, but can be held in parallel", however, he noted that the two issues only can be discussed simultaneously after the process of the DPRK's denuclearization gains driving force.

As for the sanctions imposed on the DPRK, Wi said the United Nations Security Council has its consistent stance that the sanctions can only be removed after the DPRK makes progress in its denuclearization process, and both Seoul and Washington remained a clear position on this issue.

"The international community imposed the sanctions on North Korea (DPRK) due to its nuclear test, so the UN Security Council will only consider removing the sanctions after the North (DPRK) makes essential change in its stance on the denuclearization," Wi said.

Wi paid a visit to the United States on Jan. 20-23. During his four-day stay, the South Korean top nuclear envoy met with his U.S. counterpart Sung Kim and several other officials, including Deputy Secretary of State James Steinberg and Special Representative for the DPRK Policy Stephen Bosworth, to coordinate stance on the nuclear issue and latest remarks mad by the DPRK.

The DPRK on Jan. 18 demanded negotiating a peace treaty and lifting sanctions before it returns to the six-party nuclear disarmament talks.