The five permanent members of the UN Security Council as well as Japan and the Republic of Korea (ROK) are still engaging in negotiations on a UN resolution concerning the recent nuclear test of the Democratic People's Republic of Korea (DPRK), diplomats said on Tuesday.

"We continue to engage in intense and productive negotiations," U.S. Ambassador to the UN Susan Rice told reporters on Tuesday afternoon following discussions with her counterparts in the UN headquarters.

"We're making progress but we're not done yet," said Rice. "We're all working through a large set of very complex, difficult issues, and this is a very technical endeavor. We are consulting amongst each other and with our capitals and we'll get it done as soon as we can get it done."

Rice said she is hopeful that "this will be concluded relatively soon," but declined to give a more specific prediction.

Japanese UN Ambassador Yukio Takasu said concerned countries still need more time to continue their efforts.

"We have been working continuously. Over the weekend, we have been also in touch," he said, adding that consultations will go on Tuesday afternoon.

The Security Council voiced "the strong opposition to and the condemnation of" the DPRK nuclear test on May 25, vowing to prepare a strong response to Pyongyang.

Over the past two weeks, the five permanent members of the Security Council -- Britain, China, France, Russia and the United States -- along with Japan and the ROK have been in intense negotiations on the content of the resolution.

Japan is now a non-permanent member of the 15-member Council.

The DPRK has been under UN sanctions that prevent the nation from nuclear and ballistic activity since its first atomic test in2006. An April 5 rocket launch, which the DPRK said put a satellite into orbit, prompted the Security Council to adopt a presidential statement to condemn the launch and tighten the sanctions.