Obama vows to defend Japan with US nuclear umbrella

President Barack Obama promised Wednesday a "steadfast" commitment to defend Japan under the US nuclear umbrella in the wake of North Korea's nuclear test, the White House said.

In a telephone call with Japanese Prime Minister Shinzo Abe, Obama "reaffirmed that the United States remains steadfast in its defense commitments to Japan, including the extended deterrence offered by the US nuclear umbrella," a White House statement said.