US Defense Secretary Ashton Carter attends the keynote address and opening dinner of the Shangril-La Dialogue in Singapore, May 29, 2015. The 14th Shangri-La Dialogue, widely recognized as Asia-Pacific's foremost defense and security summit, kicked off on Friday in Singapore. (Xinhua/Then Chih Wey)

Commander of US Pacific Fleet Admiral Harry Harris Jr. (R) attends the keynote address and opening dinner of the Shangril-La Dialogue in Singapore, May 29, 2015. The 14th Shangri-La Dialogue, widely recognized as Asia-Pacific's foremost defense and security summit, kicked off on Friday in Singapore. (Xinhua/Then Chih Wey)

Singapore Prime Minister Lee Hsien Loong delivers a keynote address at the opening dinner of the Shangril-La Dialogue in Singapore, May 29, 2015. The 14th Shangri-La Dialogue, widely recognized as Asia-Pacific's foremost defense and security summit, kicked off on Friday in Singapore. (Xinhua/Then Chih Wey)

German Defence Minister Ursula von der Leyen (R) and Malaysian Defense Minister Hishammuddin Hussein (C) attend the keynote address and opening dinner of the Shangril-La Dialogue in Singapore, May 29, 2015. The 14th Shangri-La Dialogue, widely recognized as Asia-Pacific's foremost defense and security summit, kicked off on Friday in Singapore. (Xinhua/Then Chih Wey)

US Defense Secretary Ashton Carter (R) and Malaysia's Defense Minister Hishammuddin Hussein attend the keynote address and opening dinner of the Shangril-La Dialogue in Singapore, May 29, 2015. The 14th Shangri-La Dialogue, widely recognized as Asia-Pacific's foremost defense and security summit, kicked off on Friday in Singapore. (Xinhua/Then Chih Wey)

Singapore Prime Minister Lee Hsien Loong delivers a keynote address at the opening dinner of the Shangril-La Dialogue in Singapore, May 29, 2015. The 14th Shangri-La Dialogue, widely recognized as Asia-Pacific's foremost defense and security summit, kicked off on Friday in Singapore. (Xinhua/Then Chih Wey)

Policemen patrol outside Shangri-La hotel where the Shangri-La Dialogue is held in Singapore, May 29, 2015. The 14th Shangri-La Dialogue, widely recognized as Asia-Pacific's foremost defense and security summit, kicked off on Friday in Singapore. (Xinhua/Then Chih Wey)

Singapore Prime Minister Lee Hsien Loong delivers a keynote address at the opening dinner of the Shangril-La Dialogue in Singapore, May 29, 2015. The 14th Shangri-La Dialogue, widely recognized as Asia-Pacific's foremost defense and security summit, kicked off on Friday in Singapore. (Xinhua/Then Chih Wey)

Admiral Sun Jianguo (C), vice chief of staff of China's People's Liberation Army (PLA) attends the keynote address and opening dinner of the Shangril-La Dialogue in Singapore, May 29, 2015. The 14th Shangri-La Dialogue, widely recognized as Asia-Pacific's foremost defense and security summit, kicked off on Friday in Singapore. (Xinhua/Then Chih Wey)

US Defense Secretary Ashton Carter addresses the first plenary session of the Shangri-La Dialogue in Singapore, May 30, 2015. The 14th Shangri-La Dialogue, widely recognized as Asia-Pacific's foremost defense and security summit, kicked off on Friday in Singapore. (Xinhua/Then Chih Wey)

US Defense Secretary Ashton Carter addresses the first plenary session of the Shangri-La Dialogue in Singapore, May 30, 2015. The 14th Shangri-La Dialogue, widely recognized as Asia-Pacific's foremost defense and security summit, kicked off on Friday in Singapore. (Xinhua/Then Chih Wey)

US Defense Secretary Ashton Carter addresses the first plenary session of the Shangri-La Dialogue in Singapore, May 30, 2015. The 14th Shangri-La Dialogue, widely recognized as Asia-Pacific's foremost defense and security summit, kicked off on Friday in Singapore. (Xinhua/Then Chih Wey)