A U.S. government official says Washington has clearly conveyed to North Korea that it needs to take three preliminary steps for the resumption of the six-way nuclear talks.

The official made the remark on Thursday when he met with reporters in San Francisco that were covering the annual ministerial meeting between the U.S. and Australia.

The official said that when U.S. Special Representative for North Korea Policy Stephen Bosworth met with the North’s First Vice Foreign Minister Kim Kye-kwan in New York in late July, Bosworth clearly stated the three steps the North needs to take for the resumption of the nuclear negotiations.

The official said Washington is waiting for a sign from Pyongyang to make those necessary moves.

Moreover, the official also said the U.S. is working closely with South Korea on issues regarding the North and is monitoring the North’s diplomatic contacts, including a recent contact with Russia.

The three steps mentioned by the official are likely to be improving ties with South Korea, the suspension of nuclear activities including uranium enrichment efforts, and the deferral of further missile tests.