President Barack Obama and Prime Minister Shinzo Abe may be able to declare next week that the U.S. and Japan have all but completed their part of negotiations on a Trans-Pacific Partnership agreement, Japan's ambassador to the U.S. said.

Kenichiro Sasae said in Washington that while some issues remain to be settled on autos and agriculture, he hopes Abe and Obama will announce agreement on the trade pact when the Japanese leader visits the White House on April 28.

"All the gaps are substantially narrowed," Sasae said Tuesday at the Center for Strategic and International Studies. "We are in the final stage."