Those pre-talk efforts culminated Monday in a rare face-to-face meeting between the top U.S. and North Korean negotiators.
The chief U.S. envoy, Assistant Secretary of State Christopher Hill, said the two sides were "just trying to get acquainted, review how we see things coming up and compare notes."
Despite the renewal of talks, negotiators from the United States, North Korea and the other four nations -- South Korea, Russia, China and Japan -- cautioned not to expect a major breakthrough in the negotiations, which are set to wrap up by the end of the week.
"We would like to make some measurable progress, progress we can build on for a subsequent round of negotiations," Hill told reporters on arrival in Beijing.
Officials from North and South Korea, who spent much of the weekend in two-way talks, declared on Sunday they wanted to see "substantial progress" as a result of the meetings and hoped for a framework for a nuclear-free Korean peninsula.
Official newspapers in North Korea, including the state-run Rodong Sinmun, have stated the clear goal of Pyongyang is a commitment from the United States to not promote the end to the Stalinist government headed by Kim Jong Il, nor launch any offensive military operation against the isolated nation.
"If the United States drops its ambition for a regime change and opts for peaceful coexistence ... the talks can make successful progress and settle the issue of the denuclearization of the peninsula," the paper said Sunday, according to the North's official Korean Central News Agency.
The newspaper accounts follow a statement Friday from the North Korean Foreign Ministry that said a formal peace treaty to end the 1950-53 Korean War would be an appropriate way to begin normalizing U.S.-North Korean relations.
U.S. officials have said before any major steps can be made toward normalizing relations, the communist nation must forego its nuclear weapons program and submit to international inspections.
Despite these continuing differences, Chinese Foreign Minister Li Zhaoxing urged the visiting delegations at a banquet on Monday night to seize these renewed talks as an opportunity to achieve tangible results.
"From my perspective, what we are looking for from the six-party talks is not just talks themselves," Reuters quoted Li as saying. "We want to achieve progress and development through the talks.
American officials have said they recognize no matter how much is achieved, it will be important to maintain the momentum created by renewing negotiations.
"We're planning to stay as long as it's useful to stay," an American official told Reuters anonymously. "I think everyone is aware we cannot have another situation where we go another 13 months without talks."
Despite diplomatic comments about the desire for progress in this week's talks, experts remain skeptical.
"China deserves credit for putting together these talks, but we can't expect much progress," Sun Zhe, an expert on Chinese-American relations at Fudan University in Shanghai, told the International Herald Tribune. "China is just a middleman between the U.S. and North Korea, and what North Korea wants, the U.S. won't give."
North Korea and the United States have been at odds over Pyongyang's nuclear ambitions for years, especially since October 2002, when U.S. Assistant Secretary of State James Kelly said the North told him it had a secret weapons program based on enriched uranium.
The reclusive communist government responded to international pressure by pulling out of the international accord aimed at preventing the spread of nuclear weapons and by expelling U.N. observers sent to monitor the North's work.
North Korea has publicly denied it has a uranium program in addition to its known plutonium-based program and in February, the North claimed it had nuclear weapons. That claim has not been verified and Pyongyang has not conducted any known nuclear test.