A senior US diplomat has arrived in Japan for fresh talks aimed at reviving stalled negotiations on North Korea's nuclear programme.
Mr Hill said North Korea had nothing to gain from boycotting talks
Christopher Hill, who will also hold talks in China and South Korea, said his visit came during a "very difficult period" in relations with Pyongyang.
He said North Korea had shown no interest in returning to multilateral talks on its nuclear ambitions.
Tensions have remained high since the North's missile tests in early July.
Mr Hill is due to meet officials in the Chinese capital, Beijing, on Tuesday, followed by talks in Chengdu, Guangzhou and Shanghai. He will then move on to Seoul, a US embassy statement said.
Mr Hill said that the US position on six-nation talks with Pyongyang, deadlocked since September 2005, had not changed.
"We have no new proposals. We have no incentives, packages, or anything like that," he told journalists in Tokyo. "All we have is a September agreement now unfortunately one full year old."
The agreement, which promised economic aid in return for Pyongyang scrapping its nuclear programme, fell apart over disagreements on how to implement it.
But Mr Hill urged North Korea to re-engage in dialogue.
"There is no reason for the DPRK (North Korea) to stay away from the diplomatic process and my government is very much committed to these talks," he said.
North Korea provoked international concern when it launched seven missiles, including a new long-range weapon capable of hitting parts of the US, on 5 July.
Some reports suggest the North may be planning more tests
There has also been further speculation in the US and South Korean media that the North may be planning an underground nuclear test.
But South Korean and US officials have played down the reports, saying there is no clear evidence anything is being planned.
Mr Hill called on Pyongyang to reconsider any further tests.
"I think all governments in the world have made very clear that it would be a very unwelcome development, and that the DPRK should really think long and hard for it to take such a provocative step," he said.