The United States confirmed the sale to Taiwan of an advanced missile system worth almost $700 million which has been battle-tested in Ukraine, its second weapons package in a week bringing the total of $1 billion, and reaffirmed support for Taipei.

In the Indo-Pacific region, only Australia and Indonesia now operate the system, three of which the United States said last year Taiwan would receive as part of a $2-billion weapons sale.

The National Advanced Surface-to-Air Missile System (NASAMS) medium-range air defence solutions, as they are called, are made by RTX and are a new weapon for Taiwan.

The Pentagon said the company was given a firm fixed-price contract for procurement of the NASAMS units, with work estimated to be completed in February 2031.

"Fiscal 2026 foreign military sales (Taiwan) funds in the amount of $698,948,760 were obligated," it said in a statement on Monday.

RTX did not immediately respond to a request for comment.

Used in Ukraine to defend against the Russian invasion, the NASAMS system offers a sharp boost in air defence capabilities that the United States is exporting to Taiwan as demand for it surges.

'ROCK SOLID' US SUPPORT

"It should be clear today and will remain clear into the future that America's commitments to Taiwan are rock solid," Raymond Greene, the de facto US ambassador in Taipei, told an event of the American Chamber of Commerce in Taiwan on Tuesday.

"We are backing these words with actions, with a focus on supporting Taiwan's efforts to achieve peace through strength. Nowhere is this more apparent than in our growing defence industrial cooperation."

Thursday's US approval of the sale of fighter jet and other aircraft parts to Taiwan for $330 million was its first such deal since President Donald Trump took office in January, prompting thanks from Taipei and anger in Beijing.

The arms sales news comes amid a worsening diplomatic crisis between Beijing and Tokyo over Taiwan, claimed by China as its own territory, although Taipei's government rejects Beijing's sovereignty claims.

On Sunday, Chinese coast guard ships sailed through waters around a group of East China Sea islands controlled by Japan but claimed by China.

Japan said it also scrambled fighter jets on Saturday, after China flew a drone between Taiwan and Japan's westernmost island of Yonaguni.

Asked about the tension on Wednesday, Taiwan Defence Minister Wellington Koo said China should not resort to force to resolve disputes.

"China should abandon its thinking of using force to resolve things," he told reporters.

Taiwan's military is beefing up its armaments to better tackle any attack from China, through efforts such as building its own submarines to defend vital maritime supply lines.

China's military operates around Taiwan on an almost daily basis in what Taipei views as a "grey zone" strategy to test and exhaust Taiwan's forces.

Despite a lack of formal diplomatic ties, the United States is bound by law to provide Taiwan with the means to defend itself, to the constant anger of Beijing.