WASHINGTON (REUTERS) - The US State Department has approved the potential sale of military technical assistance to Taiwan worth an estimated US$108 million (S$151 million), the Pentagon said on Friday (July 15).

China has never renounced the use of force to bring Taiwan under its control, and the democratically governed island has complained of increased military pressure from Beijing to try and force it to accept its sovereignty.

The United States has only unofficial relations with Taipei.

But US law requires Washington to provide Taiwan with the means to defend itself, and President Joe Biden's administration has vowed to step up engagement with the island.

Taiwan requested the latest assistance, including spare and repair parts for tanks and combat vehicles, and US government and contractor technical and logistical support, the Pentagon said.

"The proposed sale will contribute to the sustainment of the recipient's vehicles, small arms, combat weapon systems, and logistical support items, enhancing its ability to meet current and future threats," the Pentagon's Defence Security Cooperation Agency said in a statement.

It would also enhance Taiwan's military interoperability with the United States and other allies, and the island's armed forces would have no difficulty absorbing the equipment and support, it added.

The State Department notification does not indicate that a contract has been signed or that negotiations have concluded.

However, Taiwan's Defence Ministry said the deal was expected to "become effective" within a month.

"In the face of the expanding military threat of the Chinese Communists, properly maintaining equipment is as important as newly purchased weapons and equipment," it added in a statement.

Successive US administrations have urged Taiwan to modernise its military to become a "porcupine" that is hard for China to attack, advocating the sale of inexpensive, mobile, and survivable - or "asymmetric" - weapons that could outlast any initial assault by China's larger military.

Some US business groups, however, have criticised the Biden administration's Taiwan arms sales policy, arguing it is too restrictive and fails to address challenges posed by China's military.

US-Taiwan Business Council President Rupert Hammond-Chambers welcomed the announcement in a statement, but said it was a sign the administration was focused on sustainment and munitions support for Taiwan, and that force modernisation of its military "is no longer a priority."