The deal includes anti-missile defences and helicopters
The Pentagon has notified Congress of a proposed arms sale to Taiwan, worth $6bn (£3.7bn).
The weapons, including helicopters and anti-missile defences, are part of a package first pledged by the Bush administration.
Beijing considers the self-governed island a breakaway province of China and reacted angrily, saying the move would "seriously damage" its US ties.
Taiwan split from China at the end of the country's civil war in 1949.
Beijing has hundreds of missiles pointed at the island and has threatened in the past to use force to bring it under its control.
Beijing warning
The $6.7bn (£4.2bn) package does not include F-16 fighter jets, an item highly desired by Taiwan's military.
PROPOSED ARMS SALE 114 Patriot missiles ($2.81bn) 60 Black Hawk helicopters ($3.1bn) Communication equipment ($340m) 2 Osprey mine-hunting ships ($105m) 12 Harpoon missiles ($37m) Source: Defense Security Co-operation Agency
The notification to Congress by the Defense Security Co-operation Agency is required by law and does not mean the sale has been concluded.
US lawmakers have 30 days to comment on the proposed sale, Associated Press reported. If there are no objections, it would proceed.
The arms package includes 114 Patriot missiles, 60 Black Hawk helicopters and communications equipment for Taiwan's F-16 fleet, the agency said in a statement.
Chinese Vice Foreign Minister He Yafei said the proposals would have a "serious negative impact" on co-operation between the US and China.
In remarks published on the website of the Chinese Foreign Ministry, he said the Chinese government was "strongly indignant" about the arms sales.
Beijing has previously warned the US not to go ahead with arms sales to Taiwan. Ties between China and the US are already strained by rows over trade and internet censorship.
The DSCA said the proposed sale would support Taiwan's "continuing efforts to modernise its armed forces and enhance its defensive capability."
It added: "The proposed sale will help improve the security of the recipient and assist in maintaining political stability, military balance, and economic progress in the region."
The US is the leading arms supplier to Taiwan, despite switching diplomatic recognition from Taipei to Beijing in 1979.
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The US Department of Defense has notified Congress of a potential arms sale to Taiwan, with a value of $6 billion, that was first pledged by the Bush administration.

The deal, that would include helicopters and anti-missile defences, angered China, who stated that the move would "seriously damage" US–China relations, as Beijing considers the island to be a break-away province of China, having split away after civil war in 1949.

There is a stand-off between China and Taiwan.  China has a large number of weapons aimed at Taiwan, and has threatened to use them in the past.  Taiwan denounces this, warning that, if 1,500 missiles were not removed, relations between the two nations would deteriorate. 

The act of notifying Congress is a legal requirement and does not mean that the sale will go ahead. A thirty-day deadline is in place for politicians to decide on the proposition before it goes ahead. In a statement, the Pentagon listed the items being negotiated over, including 114 Patriot missiles and sixty helicopters. It will also include two minesweepers. The US is the main arms supplier for Taiwan.

General James L. Jones, the National Security Advisor for the Obama administration, said that China had been fully consulted about the deal. "We all recognise that there are certain things that countries will do periodically that may not make everybody completely happy," he stated. However, he maintained that the US was "bent towards a new relationship" between themselves and China.

A spokesman for the Chinese embassy in Washington, D.C., Wang Baodong, said yesterday that the arms sale was a "gross intervention into China's internal affairs". He went on to assert that the trade "seriously endangers China's national security".

Ties between the United States and China, already stretched by the recent row over internet censorship, in which Google threatened to withdraw its presence in the country, have been strained by the announcement. China maintains, according to a press release on 22 January, that the Internet in their country is "open", with the "most vibrant" sites based in China. Beijing wishes the United States to "respect each other's core interest", and to "ensure the healthy stable development" of their relationship.