BEIJING (REUTERS) - China's defence ministry said on Thursday (Aug 30) that navy chief Shen Jinlong will visit the United States in September, amid an escalating trade row that threatens to spill into other areas of tension between the two countries.

The announcement the ministry's spokesman Wu Qian comes two months after US Defence Secretary Jim Mattis visited Beijing.

China said that visit yielded positive results, and Defence Minister Wei Fenghe has accepted an invitation to visit the United States before the end of the year.

Ties between the two countries have been strained on a number fronts in recent months.

In May, the Pentagon withdrew an invitation to China to join a multinational naval exercise, citing China's military moves in the South China Sea. The US decision upset Beijing and was raised during the visit by Mattis, Chinese officials said at the time.

Beijing and Washington are also locked in a spiraling trade row that is threatening to worsen the relationship across the board, from cooperation on North Korea to the South China Sea.

China has denied that it "does deals" on issues of foreign policy, such as linking trade tensions with the United States to its willingness to impose sanctions on North Korea.

US attempts to ensure freedom of navigation in the disputed waters of the South China Sea, where China claims sovereignty over some small islands, have also irritated Beijing.

US backing for self-ruled Taiwan have also fuelled China's suspicions in recent months, as the current US administration has signalled fresh support towards the island that Beijing claims as its own.