The package would include as much as $650-million in continued support for a surveillance radar sold earlier, about $90-million for roughly 100 Sidewinder air-to-air missiles as well as about 60 additional anti-ship Harpoon missiles, the official said. Both weapons have been sold to Taiwan previously.

The State Department informally notified Congress of the sale late on Monday. Even though it offers Taiwan no new military capability, the move could prompt protests from Beijing, which has said American arms sales to Taiwan are a threat to its security and a violation of the agreements that established diplomatic relations with Washington. 

The Chinese Foreign Ministry in Beijing didn’t immediately respond to a request for comment on the sale. The planned arms sale was reported by Politico earlier on Monday. 

The notification marks the beginning of several weeks of staff consultations that will result in a formal arms-sale proposal from the State Department. With support for Taiwan running high among both Republicans and Democrats in Congress, the package will likely face little resistance from lawmakers.

A separate person familiar with the matter said there have been several conversations between the administration and Congress about arms sales to Taiwan. 

A spokesperson for the US National Security Council, who asked not to be identified, declined to respond in detail and said only that the US would continue fulfilling its responsibilities under the Taiwan Relations Act to support Taiwan’s self-defence. A State Department spokesperson said, as a matter of policy, that the department does not publicly comment or confirm proposed defence sales until they have been formally notified to Congress.

The sale would be the largest since a $2.4-billion deal including Harpoon missiles in October 2020, and the largest since President Joe Biden took office. The president is facing calls to accelerate American weapon transfers to Taiwan to deter China from acting militarily against the democratically governed island and avoid a repeat of Russia’s invasion of Ukraine. 

Taiwan last week proposed raising its total spending on the military by almost 14% next year. 

Earlier this month, House Speaker Nancy Pelosi became the highest-ranking US official in a quarter century to visit Taiwan, prompting Beijing afterward to conduct military drills and fire missiles over the island for the first time. Chinese warplanes have flown across the US-established median line that divides the Taiwan Strait – once a rare occurrence – on all but one day since Pelosi’s arrival on 2 August.

Since then, Senator Edward Markey, a Massachusetts Democrat, and Senator Marsha Blackburn, a Tennessee Republican, have also made high-profile trips there. Taiwanese President Tsai Ing-wen has welcomed the visits from the US lawmakers as an “active show of strong support of the US Congress”, adding they had “reinforced Taiwan’s determination to defend itself.” BM