Condoleezza Rice, the US secretary of state, had pressed North Korea to give a preliminary commitment to complete a nuclear disarmament deal.
She said the talks were a "good meeting, [with] no surprises".
"The atmosphere was very good... It was not a stand-off with everybody stating their positions. It was interactive.
"Everyone essentially confirmed [previous agreements] and the need to move rapidly to finish phase two obligations," she said.
Earlier Ri urged the US to drop North Korea from its list of state sponsors of terrorism by August in accordance with agreements made at the six-party talks which began in 2003.
"On the United States side, they also took an action although it is incomplete," he told reporters.
"I think what is most important is to lift the sanctions fully and in a full-phase way to drop the hostile policy against the DPRK," he told reporters.
The meeting examined methods of verifying North Korea's nuclear programme, Rice said, with "a sense of urgency about moving on and a sense that we cannot afford to have another hiatus of several months".
Before the meeting, Rice said she would deliver "a very strong message" that the denuclearisation process "really needs to be completed, and that it has to be a verification protocol that can give us confidence".
The four-page draft document presented to North Korea earlier this month calls for intrusive inspections of Pyongyang's nuclear facilities, soil sampling, interviews with key scientists and a role for UN atomic experts.
When asked when the verification process would begin, Ri only said that North Korea was committed to fulfil its six-party commitments by an October deadline.
"We [need] a way to address proliferation as well as all nuclear programmes, including highly enriched uranium"
US secretary of state
"Under the agreement of the heads of delegation of the six parties there was discussion and they agreed on establishing a mechanism for verification under the six-party framework and also a monitoring system."
"So under that agreement, all respective parties will go for full implementation by the end of the coming October."
Ri said that North Korea hoped the unprecedented ministerial meeting would be a driving force toward the full denuclearisation of his country.
Christopher Hill, the chief US negotiator, said late on Tuesday that he believed the meeting would "give some indication of the amount of effort the North Koreans have put into completing this verification protocol".
He said the goal was to reach a formal agreement on the document by mid-August after negotiations on the fine points, some of which the North Koreans have already objected to.
"They made some preliminary comments and indicated some problems with it," he said. "But we have to see what their considered comments back from the capital are."
Verification is expected to take months to finish and the Bush administration is eager to make quick progress in its last six months in office.
Proliferation and uranium
The meeting comes amid positive developments in the six-nation effort to get the North to denuclearise, with North Korea submitting a long-delayed list of its nuclear programmes involving plutonium last month and blowing up the cooling tower at its main nuclear reactor.
But its report did not include details about nuclear weapons, an alleged uranium enrichment program and possible nuclear proliferation with country's such as Syria.
The US announced it would remove the North from its "terrorism" blacklist and relaxed some economic sanctions after Pyongyang handed over its report, but Rice made clear that concerns uranium and proliferation still have to be addressed if progress is to continue.
The foreign ministers of South Korea, Japan, China and Russia were also present at the discussions.