WASHINGTON (Kyodo) Japan and the United States must join forces to eliminate nuclear weapons, former Prime Minister Shinzo Abe and U.S. Vice President Joe Biden agreed Wednesday.

The two reached the accord in talks at the White House as Abe handed Biden a letter for U.S. President Barack Obama from Prime Minister Taro Aso.

Abe is in Washington to deliver a keynote speech at a Japan-U.S. maritime security symposium Friday.

In the letter, Aso welcomed Obama's recently unveiled vision for a world without nuclear weapons and called for bilateral cooperation for disarmament, Abe said.

Abe said he backs the Obama administration's plan to ratify the Comprehensive Test Ban Treaty, which the administration of his predecessor, George W. Bush, rejected.

"In handing over the letter, I told the vice president that if the United States ratifies the CTBT, it will have an enormous impact on the world and send a very strong message," Abe said.

"I also told him that Japan and the United States should jointly encourage other nations to join us in trying to put the CTBT into force," he said.

Biden was quoted as replying that it is heartening to have secured support from Japan, a U.S. ally, and that Washington is willing to work in concert with Tokyo to promote nuclear disarmament.

Biden was also quoted as saying that if nuclear disarmament is pushed for by the U.S., it will not affect the nuclear umbrella Washington guarantees its allies.