Vice President Cheney has arrived in Japan on the first leg of a three-nation Asian tour overshadowed by the bloody uprising in Iraq.

Mr. Cheney is expected to urge Japan to keep its troops in Iraq, despite the kidnapping earlier this week of three Japanese civilians. Iraqi insurgents have threatened to execute the hostages unless Japan withdraws all its troops from Iraq by Sunday night.

Prime Minister Junichiro Koizumi says he will not bow to the demands.

At a refueling stop in Alaska late Friday, Mr. Cheney said fighting international terrorism will require coordination with U.S. allies around the world. He said America's will is being tested, but that it is essential for the United States to finish its work in both Iraq and in Afghanistan.

Mr. Cheney's week-long trip will also take him to China and South Korea, where he will hold talks on efforts to curb North Korea's nuclear ambitions.

China is not a member of the U.S.-led coalition in Iraq, but South Korea is planning to send additional troops to help with peacekeeping efforts in Iraq. Eight South Korean missionaries were kidnapped in Iraq this week, but one escaped and the others were released.

The vice president is expected to tell Japanese and South Korean leaders that the recent increase in violence in Iraq will not weaken the United States' commitment to establishing a democratic government in Baghdad.

Mr. Cheney will also ask China to consider revaluing its currency, the yuan.

This is Mr. Cheney's third overseas mission as vice president since 2001. His Asia trip originally was scheduled for last year, but it was postponed because of the Iraq war.