U.S. President Barack Obama and Prime Minister Taro Aso spoke Friday by telephone, discussing North Korea and aid to Pakistan, Chief Cabinet Secretary Takeo Kawamura said.

Aso and Obama spoke for about 15 minutes, Kawamura told reporters in Tokyo.

The two leaders agreed to work closely to restart the six-nation talks on dismantling North Korea's nuclear weapons program, according to a statement.

Kim Jong Il's government withdrew from the negotiations after the United Nations condemned its April 5 missile test, which the communist state claimed was an attempt to put a satellite into orbit.