After agreeing on a moratorium on long-range missile tests and nuclear activity during high-level talks in Beijing early this year, North Korea announced plans to send an Earth observation satellite into orbit this month.
Washington had said it viewed the plans as provocative and Tokyo said it would intercept the rocket should its flight plan cross Japanese territory.
A U.S. State Department official told the Yonhap news agency in South Korea that world attention might send the wrong message to the Democratic People's Republic of Korea.
"We call on the international community to abstain from taking any actions, such as sending observers, that might be seen as endorsing a launch that would be in blatant defiance of the DPRK's international obligations and commitments," the official said on background. "The United States will not send any observers."
The U.S. Defense Department noted the planned launch would be in violation of U.N. Security Council Resolutions 1718 and 1874, banning North Korea's use of ballistic missile technology.
A delegation of five U.S. lawmakers is to arrive for a three-day visit to Seoul at the end of the week, Yonhap adds. They are to discuss the security situation in the Korean Peninsula and visit the demilitarized zone separating both Koreas.