The State Department informed Congress on Tuesday of the $80 million package, which is small compared with recent sales to Taiwan but marks the first assistance to Taipei under the Foreign Military Financing program, which generally involves grants or loans to sovereign countries.

The move is sure to anger China. For five decades, the United States has officially only recognized Beijing although Congress, under the Taiwan Relations Act, requires the supply of weapons to the self-governing democracy for its defense.

Successive US administrations have done so through sales rather than direct aid to Taiwan, with formal statements speaking in terms of business transactions with the island's de-facto embassy in Washington.

The State Department insisted that the first-ever aid under the program did not imply any recognition of sovereignty of Taiwan.

"Consistent with the Taiwan Relations Act and our longstanding One China policy, which has not changed, the United States makes available to Taiwan defense articles and services necessary to enable it to maintain a sufficient self-defense capability," a State Department spokesperson said.

"The United States has an abiding interest in peace and stability in the Taiwan Strait, which is critical to regional and global security and prosperity."