Japan and the United States should strengthen bilateral ties as China increases its presence in the South China and East China seas, Prime Minister Shinzo Abe and the visiting chairman of the U.S. Senate Foreign Relations Committee agreed Thursday.

Abe told Robert Menendez at a meeting in Tokyo that the alliance's importance is "increasing more and more" as the "strategic environment" in the Asia-Pacific region undergoes drastic change.

Menendez, making his first trip to Asia since becoming the committee chairman, said Japan is the cornerstone of U.S. interests in East Asia, with both Tokyo and Washington sharing such values as democracy and human rights.