CHIAYI, Taiwan, (Reuters) - Taiwan President Tsai Ing-wen lauded military cooperation with Washington on Thursday as she commissioned the first combat wing of F-16 fighters upgraded with U.S. help to bolster the island's defences during rising tensions between Taipei and Beijing.

Frequent Chinese and U.S. military exercises in the region have raised fears of conflict touched off by a crisis over democratically-ruled Taiwan, which Beijing claims as its own territory.

Tsai told a ceremony at an air base in the southern Taiwanese city of Chiayi to unveil the first squadron of its most advanced F-16s, the F-16V, that the project showed the firm commitment of the Taiwan-U.S. partnership.

"I believe that as long as we adhere to the values of democracy and freedom, there will be more like-minded countries standing on the same front with us," she said, speaking on the same stage as the top U.S. diplomat in Taiwan, Sandra Oudkirk.

The United States has no official diplomatic ties with Taiwan but is the island's main international backer and arms supplier, to Beijing's fury.