The United States unveiled a Taiwan weapons aid package worth up to $345 million on Friday, a move likely to anger China even as the Biden administration declined to publicly provide details on the arms in the package.

Congress authorized up to $1 billion worth of Presidential Drawdown Authority weapons aid for Taiwan, which strongly rejects Chinese sovereignty claims, in the 2023 budget. Beijing has repeatedly demanded the United States, Taiwan's most important arms supplier, halt the sale of weapons to the island.

In recent weeks, four sources told Reuters the package was expected to include four unarmed MQ-9A reconnaissance drones, but noted their inclusion could fall through as officials work through details on removing some of the advanced equipment from the drones that only the US Air Force is allowed access to.

The formal announcement did not include a list of weapon systems being provided.

Taiwan’s defence ministry thanked the US for its “firm security commitment,” adding in a statement it will not comment on the package details due to the “tacit agreement” between the two sides.

Among the issues that could confound the inclusion of the drones was who would pay for their alterations, one of the people briefed on the matter said previously. Reuters could not determine if the drones were still part of the package.

Taiwan had previously agreed to purchase four, more advanced, MQ-9B SeaGuardian drones, made by General Atomics, which are slated for delivery in 2025.

China views democratically governed Taiwan as its territory and has increased military pressure on the island over the past three years. It has never renounced the use of force to bring the island under its control. Taiwan strongly rejects China's sovereignty claims and says only Taiwanese people can decide their future.

Foreshadowing the upcoming aid, Secretary of Defense Lloyd Austin on May 16 told a Senate panel: “I’m pleased that the United States will soon provide significant additional security assistance to Taiwan through the Presidential Drawdown Authority that Congress authorized last year.”

Earlier this month, the top US general said the United States and its allies need to speed up the delivery of weapons to Taiwan in the coming years to help the island defend itself.

The Presidential Drawdown Authority (PDA) has been used on an emergency basis to expedite security assistance to Ukraine by allowing the president to transfer articles and services from US stockpiles. The Taiwan PDA, however, is a non-emergency authority approved by Congress last year.