Japan has recognized the United States' former Defense Secretary Robert Gates and former National Security Adviser Stephen Hadley for their contributions to a strengthening of the bilateral alliance.

In a decoration ceremony in Washington on Thursday, a message from Japanese Prime Minister Shinzo Abe was read by an embassy official, saying Japan remembers the assistance and disaster relief, dubbed Operation Tomodachi, provided under Gates' leadership in the wake of the devastating earthquake and tsunami that hit northeastern Japan in March 2011.

"The people of Japan will never forget the dedication and support (shown) by the U.S. military under the leadership of Secretary Gates," Abe said in the message.

Abe also hailed Gates' initiatives in pushing forward the realignment of U.S. forces in Japan.

In the ceremony, Japanese Ambassador to the United States Kenichiro Sasae presented the Grand Cordon of the Order of the Rising Sun to both Gates, 74, and Hadley, 70.

Referring to the frequent interactions he had with Hadley when he was chief Cabinet secretary under Prime Minister Junichiro Koizumi, Abe said, "I still vividly remember communicating over the phone on drafting a U.N. Security Council resolution" in response to a North Korean missile launch in 2006.

Abe lauded Hadley for "actively advocating the importance of the Japan-U.S. alliance" even after retiring from his role as assistant to President George W. Bush on national security affairs.

Speaking at the ceremony, Gates underscored "the critical and enduring importance of the United States-Japanese security relationship and the close ties between our two countries."

"As we face common security challenges in Asia today, our alliance is more important than ever," he said.

Hadley cited challenges the Japan-U.S. alliance faces in the region such as the rise of China, Beijing's assertive territorial claims in the East and South China seas, as well as North Korea's development of nuclear weapons and ballistic missiles.

"But it gives me great confidence that Japan and the United States are working together, shoulder to shoulder, to address these challenges," he said.

"And of course, that's the way it should be between two such close, enduring allies."