Condoleezza Rice, currently on a visit to China, said she was encouraged by the latest moves from North Korea, which last week handed a long-awaited declaration on its past nuclear activities to China and destroyed a cooling tower at the Yongbyon nuclear plant.
The diplomat did not give a date for the next round of talks involving China, the United States, Japan, the two Koreas and Russia, but said: "I don't think it will be weeks. There are scheduling issues. We have to get people together."
Speaking after talks with Chinese President Hu Jintao and Premier Wen Jiabao, she stressed that "hard work" lay ahead in the talks process.
The demolition last Friday of the cooling tower at Yongbyon, about 100 km (62 miles) north of Pyongyang, has been received as a sign of North Korea's willingness to terminate its nuclear program. The disabling of facilities at the plant is being monitored by U.S. specialists.
The six-party talks stalled late last year, when Pyongyang missed a deadline to transfer nuclear data as part of a deal under which the North was promised economic aid and diplomatic incentives.
A U.S. cargo ship delivered several thousand tons of wheat to North Korea earlier on Monday as part of food aid to the impoverished country.
After the North submitted its nuclear declaration last Thursday, the U.S. announced it would lift unilateral trade sanctions against the country and remove it from a terrorism blacklist.
However, U.S. President George Bush said Washington continues to be concerned over North Korea's uranium enrichment activities and suspected sales of nuclear technology to other countries.
According to various estimates, Pyongyang has secretly produced about 35-50 kg of weapons-grade plutonium.
