US warns of sanctions if N Korea fires missile

Schieffer said that a test by the communist state would be a "very, very serious matter" that could be brought before the United Nations Security Council.

"I think sanctions would have to be considered but I wouldn't want to describe what actions we might take," Schieffer told Japanese reporters, as quoted by a US embassy official.

Japanese and US officials say they have seen signs that North Korea is preparing for a long-range missile test, with media reports indicating it could be imminent.