BEIJING (REUTERS) - China's Foreign Ministry said on Thursday (June 6) it is seriously concerned about US arms sales to self-ruled Taiwan, after sources told Reuters that Washington was planning a US$2 billion (S$2.73 billion) weapons sale to the island China claims as its own.

"We are severely concerned about the US move and are firmly against US arms sales to Taiwan," Foreign Ministry spokesman Geng Shuang told a daily news briefing in Beijing.

China urges the United States to stop arms sales to Taiwan and prudently deal with issues relating to Taiwan to prevent harm to bilateral relations and peace and stability in the Taiwan Strait, he added.

The United States is pursuing the sale of more than US$2 billion worth of tanks and weapons to Taiwan, four people familiar with the negotiations said, sparking anger from Beijing which is already involved in an escalating trade war with Washington.

An informal notification of the proposed sale has been sent to the US Congress, the four sources said on condition of anonymity because they were not authorised to speak about the possible deal.

The potential sale included 108 General Dynamics Corp M1A2 Abrams tanks worth around US$2 billion as well as anti-tank and anti-aircraft munitions, three of the sources said. Taiwan has been interested in refreshing its existing US-made battle tank inventory, which includes M60 Patton tanks.

The United States is the main arms supplier to Taiwan, which China deems its own and has never renounced the use of force to bring the self-ruled island under its control.

Taiwan President Tsai Ing-wen said in March Washington was responding positively to Taipei's requests for new arms sales to bolster its defences in the face of pressure from China. The US has no formal ties with Taiwan but is bound by law to help provide it with the means to defend itself.

China and the US are engaged in a fierce trade war, with clashes over Taiwan and the South China Sea exacerbating tensions.

A spokesman for the State Department, which oversees foreign military sales, said the US government does not comment on or confirm potential or pending arms sales or transfers before they have been formally notified to Congress.

The congressional notifications included a variety of anti-tank munitions, including 409 Raytheon Co and Lockheed Martin Corp-made Javelin missiles worth as much as US$129 million, two of the sources said.

The notifications also included 1,240 TOW anti-tank missiles worth as much as US$299 million, one of the sources said. There were also 250 stinger missiles worth as much as $223 million in the notification, the source said.

Stingers are often used in portable anti-aircraft weapons systems.

Taiwan's Defence Ministry confirmed it had requested those weapons and that the request was proceeding normally.

The US commitment to providing Taiwan with the weapons to defend itself helps Taiwan's military to raise its combat abilities, consolidates the Taiwan-US security partnership and ensures Taiwan's security, the ministry said in a statement.

US President Donald Trump's administration rolled out a long-awaited overhaul of US arms export policy in 2018 aimed at expanding sales to allies, saying it would bolster the American defence industry and create jobs at home.

Mr Trump's trade adviser Peter Navarro was one of the administration's architects of that policy.

Mr Navarro, a China hawk, wrote about the possible sale of tanks to Taiwan in a March opinion column in the New York Times ahead of a presidential trip to the Lima, Ohio, plant where they are made.

At a low point, the US Army had only one tank coming from the plant a month, General Dynamics CEO Phebe Novakovic said during an April conference call with investors, but said "we'll be rolling out 30 tanks a month by the end of this year", partly because of international orders.

The Pentagon announced last week it would sell 34 ScanEagle drones, made by Boeing Co, to the governments of Malaysia, Indonesia, the Philippines and Vietnam for US$47 million.

The drones would afford greater intelligence-gathering capabilities, potentially curbing Chinese activity in the region.

China claims almost all of the strategic South China Sea and frequently lambastes the United States and its allies over naval operations near Chinese-occupied islands. Brunei, Malaysia, the Philippines, Taiwan and Vietnam all have competing claims.

China's Defence Minister Wei Fenghe warned the US at the Shangri-La Dialogue in Singapore last weekend not to meddle in security disputes over Taiwan and the South China Sea.

Acting US Defence Secretary Patrick Shanahan told the meeting that the United States would no longer "tiptoe" around China's behaviour in Asia.

Taiwan's Foreign Ministry, responding to the Reuters report of planned the new arms sale, said Mr Wei's "threatening" comments and recent Chinese military drills near Taiwan showed the importance of its need to strengthen its defensive abilities.

"Going forward our government will continue to deepen the close security partnership between Taiwan and the United States," it said.