The navies of China and the United States conducted their second joint counter-piracy exercise in the Gulf of Aden on Sunday.

This sign of improved Sino-US military relations followed the return of Defense Minister Chang Wanquan from a visit to Washington last week.

Chinese and US soldiers participate in the counter-piracy exercise on the missile destroyer "Harbin" of Chinese navy in the Gulf of Aden, Aug 25, 2013. The Chinese and US navies conducted a joint counter-piracy exercise in the Gulf of Aden on Saturday and Sunday. [Photo/Xinhua]

The Chinese naval contingent was taking part in escort missions before the two-day exercise, which started on Saturday. It was the 14th Chinese naval contingent to be deployed to the Gulf of Aden.

Missile-equipped destroyers, supply ships, ship-based helicopters and task forces from both sides took part in the drill. Among them was the US navy's escort destroyer USS Mason.

The joint exercise for the first time included joint operations by special task forces and helicopter surveillance on maritime targets during the night.

The joint exercise was aimed at strengthening exchanges and cooperation between the two militaries on the maintenance of safety of international waters, a Chinese officer said.

In September last year, China and the US conducted their first joint anti-piracy drill, which lasted for five hours in the Gulf of Aden.

China has also agreed to participate in the 2014 Rim of the Pacific Exercise, in a sign of its willingness to improve military ties that were often disrupted by US weapons sales to Taiwan.