U.S. Ambassador Thomas Schieffer expressed concern Wednesday about a proposal by Japan's trade minister to create a 16-nation free-trade agreement in Asia and Oceania, saying it could damage U.S. interests in the region.

"What makes the United States uncomfortable is when people start talking about somehow trying to exclude the United States from Asia," the envoy said at a lecture in Tokyo. "We believe as a Pacific nation, we have tremendous interests in Asia and we want to be a part of Asia.

"If there is skepticism on our part, it only comes from the notion that somehow someone might be trying to exclude us from the area. That would be something that would not be met with favor in the United States," he said.