WASHINGTON (Reuters) - President Barack Obama spoke to Japan's Prime Minister Shinzo Abe on Wednesday about North Korea's nuclear test and reaffirmed U.S. commitments to Japan's security, the White House said in a statement.

"They pledged to work closely together to seek significant action at the United Nations Security Council and to cooperate on measures aimed at impeding North Korea's nuclear and ballistic missile programs," the White House said in a statement.

"President Obama reaffirmed that the United States remains steadfast in its defense commitments to Japan, including the extended deterrence offered by the U.S. nuclear umbrella."

Obama told Abe he looked forward to in-depth discussions with him during his visit to Washington later this month, the White House said.

(Reporting by Jeff Mason; editing by Christopher Wilson)