The United States has urged Japan not to attend the first meeting of signatories to a U.N. treaty banning nuclear weapons as an observer, according to U.S. government sources, reflecting Washington's opposition to the pact.

The Japanese government has suggested it will come into line with the United States and take a cautious approach to the issue, the sources said. Prime Minister Fumio Kishida told a parliamentary committee on Thursday that Tokyo has no "concrete plans" to attend the meeting as an observer.

The sources said the administration of U.S. President Joe Biden made the request to Japan through diplomatic channels after German political parties announced Nov. 24 that the deal for the new ruling coalition included taking part as an observer at the meeting, which is scheduled for March in Vienna.