The success of the fourth around of six-party talks on the nuclear issue of the Democratic People's Republic of Korea (DPRK) hinges on the adoption of a joint document, Russia's chief negotiator said Friday.

"Approval by all the sides of a joint document on the principles and ways leading to the demilitarization of the Korean Peninsula ... would mean a success of the fourth round's continuation," Deputy Foreign Minister Alexander Alexeyev, who led the Russian delegation to the talks in Beijing last month, told the Itar-Tass news agency.

The current round of talks, which gathered officials from the six countries involved -- China, the DPRK, the United States, South Korea, Russia and Japan -- in Beijing for 13 days last month, is now taking a recess. China announced Thursday the talks will resume Tuesday in Beijing and be open-ended.

The Russian negotiator said the talks will be time-consuming and that two or three problems remain unsettled due to serious differences between the DPRK and the United States, which "caused a break in the talks and entailed consultations in their respective capitals."

"Everybody is going to the negotiations with a certain degree of optimism, hoping that in the long run it will be possible to settle all the remaining problems" during the fourth round of talks, Alexeyev said.

Source: Xinhua