BANGKOK (Reuters) - The highest ranking U.S. officer to visit Thailand since a 2014 coup will attend a military exercise next month in what the Thai army hailed on Wednesday as a sign of improving relations.

The United States scaled down its presence at Cobra Gold, Asia’s largest annual multinational military exercise, as one of the former U.S. administration’s measures to pressure the Thai government to restore democracy.

Relations have since improved as the junta has taken steps towards holding elections - and as Thailand has grown closer to dominant regional power China.

The U.S. embassy confirmed that Admiral Harry Harris, the head of Pacific Command, would open Cobra Gold on Feb. 14. More junior officers attended the exercise in the past two years.

Harris’s attendance was planned before the inauguration of U.S. President Donald Trump, whose policy moves on Asia are closely watched after signals of potential confrontation with China over trade, Taiwan and claims in the South China Sea.

The U.S. embassy said Cobra Gold would only return to its original scope and scale once Thailand restores democracy.

“We are eager to see our cooperation fully resume with the restoration of a democratically elected civilian government,” Melissa Sweeney, a spokeswoman at the U.S. embassy in Bangkok, told Reuters.

The United States will send 3,500 personnel to the war games - slightly fewer than last year.

Thailand’s army said that Harris’s attendance at Cobra Gold sent an important signal.

“It is not common for an officer of Admiral Harris’ rank to attend these sorts of events,” said General Thanchaiyan Srisuwan, the head of the Joint Chiefs of Staff.

“It is a good signal for Thai-American relations and shows that the U.S. has given importance to this region and this exercise,” he told Reuters.

Thailand has hosted the war games since they began in 1982. This year’s event will be attended by 8,333 personnel from 29 countries.

Thailand’s links with China have grown ever stronger since the 2014 coup.

Thai officials said on Wednesday the government had approved 13.5 billion baht ($380 million) to buy a submarine from China after putting the purchase on hold last year. It will also buy new tanks and other vehicles from China.

The Thai junta held a referendum last year on a constitution to allow a general election. It was originally due to take place this year but it is not widely expected to happen before 2018.