Washington's chief diplomat on North Korea's weapons programs continues his search in Asia for a unified response to Pyongyang's recent missile launches, and has indicated some flexibility in dealing with Pyongyang. But the Japanese are demanding United Nations sanctions against North Korea, placing Japan - and the U.S. - in potential conflict with China and Russia.
U.S. Assistant Secretary of State Christopher Hill spent Saturday here in Seoul, urging senior officials to cooperate on persuading North Korea, also known as the DPRK, to return to six-party talks on Pyongyang's nuclear weapons programs.
"I think it's very important that all of us, all of the participants in the six-party process, that we speak in one voice and send a really clear message to the DPRK," he said.
In Beijing Friday, and now in Seoul, Hill's public call for "one voice" has focused primarily on ways to get North Korea back to the bargaining table.
He says Washington and Seoul both support a Chinese proposal for an "informal" meeting of the six-nation group. He also says he could oblige Pyongyang on its long-standing request for a one-on-one dialogue with Washington - although only within the six-party framework.
But the U.S., along with Britain and France, has also co-sponsored a Japanese-proposed U.N. Security Council resolution calling for sanctions against the North.
On Saturday, Japanese Foreign Minister Taro Aso vowed that Tokyo would "not compromise" on the issue.
Aso says Japan is firm on a binding resolution that includes sanctions.
Russia and China, both permanent Security Council members with veto authority over any resolution, have consistently opposed sanctions against Pyongyang. They say they prefer a non-binding statement of U.N. disapproval over Wednesday's missile tests.
South Korea says it is temporarily withholding thousands of tons of food and fertilizer aid to the North because of the missiles - but Seoul, which favors engagement with Pyongyang, is also reluctant to support punitive sanctions.
Earlier Saturday, the U.S. envoy repeated a refusal to lift sanctions Washington has unilaterally placed on a bank in Macau. The U.S. charges that Banco Delta Asia has helped North Korea launder money from illegal activities such as counterfeiting.
Pyongyang says it will return to the talks if the sanctions on the bank are lifted. Hill says the time is not right for that kind of gesture, especially with Pyongyang firing missiles in what he describes as a "truly reckless way." Hill moves on to Tokyo on Sunday.