Japan wants to hold talks with the United States to relay its strong concern over the "no first use" policy for the U.S. nuclear arsenal that is being considered by Washington, Japanese government sources said Friday.

Opponents are worried that the landmark shift in policy would undermine the credibility of the nuclear deterrence provided to Japan and other allies under the U.S. nuclear umbrella, the sources said.

U.S. President Barack Obama is expected to decide by the end of this month on whether to declare the policy shift to rule out a nuclear strike unless attacked by an adversary with nuclear weapons, a U.S. government source said.