Congress still needs to give final approval to the deal, and can raise objections to any arms sales within 30 days of the issuance of a formal notification.
Among the weapons systems in Wednesday’s deal were 11 truck-based rocket launchers made by Lockheed Martin Corp, known as the High Mobility Artillery Rocket System (HIMARS), at an estimated cost of $436.1m.
The deal also includes 135 precision-guided cruise missiles, as well as mobile light rocket launchers and air reconnaissance pods that can be attached to fighter jets.
The defence and foreign ministries in Taiwan welcomed the news, saying the weapons would help improve defensive capabilities.
“This arms sale shows that the United States attaches great importance to the strategic position of the Indo-Pacific region and the Taiwan Strait, and is actively assisting our country in strengthening our overall defence capabilities,” Taiwan’s Defence Ministry said.
Responding to the arms deal, China's Foreign Ministry said that it would have a major impact on its relationship with the US and that it would respond as necessary.
In recent years, tensions over the self-ruled island have increased as Beijing has more forcefully asserted its claim to sovereignty. In January the island re-elected incumbent president Tsai Ing-Wen, who campaigned on a ticket of defending Taiwanese sovereignty.
The arms deal also comes as relations have deteriorated between China and the US administration of Donald Trump, ahead of the 3 November US election. Mr Trump has made a tough stance against China a central theme of his foreign policy during the campaign for a second term.
Analysts say Washington has been eager to see Taiwan bolster its defence capabilities in the face of increasingly assertive moves from Beijing, which has been ratcheting up pressure on the island ever since President Tsai was first elected in 2016. Taiwan said this month that it spent almost $900m last year scrambling its air forces to meet Chinese incursions.