The chief US and South Korean negotiators in the six-nation talks on the Korea Peninsular nuclear issue said Monday they had reached "complete agreement" on how to deal with the issue, reported Yonhap.

"We had a complete agreement on how to proceed and I would say ... the US and the Republic of Korea are cooperating very very well in this very difficult matter," US chief negotiator Christopher Hill said after meeting with South Korea's Deputy Foreign Minister Song Min-soon.

"I would say we have very good understanding of this issue and very good agreement on the best tactics to bring this issue to resolution," said Hill, assistant secretary of state for East Asia and Pacific affairs.

He did not elaborate, but said the focus is still on diplomacy.

"What we're focusing on is the diplomatic track and the need to get the talks going and, more importantly, once they get going, to achieve progress in the talks," he said.

Hill arrived in Seoul on Saturday on the first leg of a trip that will also take him to China and Japan later this week, reported Yonhap.

Hill also met South Korea's Foreign Minister Ban Ki-moon and said he was pleased that Washington and Seoul "are very much in sync" with regard to the nuclear issue.

Later in the day, the US diplomat is to meet senior National Security Council official Lee Jong-seok.

Hill, the recently departed US ambassador to Seoul, took up his new job earlier this month. It is his first trip to the region in his new capacity.