Taiwan thanked the United States Tuesday for selling up to $100 million worth of equipment and services to support its air and missile defense systems.

On Tuesday, Taipei expressed "gratitude" to the United States for approving a $100 million arms sale, which will maintain its Patriot missile air defense system.

Taiwan's Presidential Spokesperson Xavier Chang indicated in a statement that "this is the second arms sale to Taiwan since President Joe Biden took office and the first time this year."

"It ... reflects the rock-solid partnership between Taiwan and the US," he added. 

Taiwan's Defense Ministry pointed out that the deal is expected to take effect sometime in March.

According to a statement from US Defence Security Cooperation Agency, the deal covers engineering support and maintenance of air defense systems and will "ensure readiness for air operations."

"The recipient will use this capability as a deterrent to regional threats and to strengthen homeland defense," said the US agency. 

The first major arms sale to Taipei under Biden was last August, which saw the approval of 40 155mm M109A6 medium self-propelled howitzer artillery systems.

China: Arms sale undermines peace and stability

For its part, Beijing opposed and condemned the latest sale, saying it "seriously undermines" US-China relations, as well as peace and stability in the Taiwan Strait. 

"China will take legitimate and strong measures to uphold its own sovereignty and security interests," pledged Chinese Foreign Ministry Spokesperson Zhao Lijian.

US-China tensions over Taiwan

Washington diplomatically recognizes Beijing over Taipei but it is also bound by Congress to sell Taiwan weapons to "defend itself".

Former US President Donald Trump increased arms sales to Taiwan during his time in office as he feuded with Beijing on a host of issues from trade to national security. 

Sales included drones, missile systems, and new-generation fighter jets.

It is noteworthy that China considers the island of Taiwan an integral part of its territory and thus has long sought to reincorporate it into the mainland.

Beijing tried to reclaim the island of Taiwan multiple times. Just southwest of Taiwan, Hainan Island, another island that almost matches Taiwan's size extends along the Chinese mainland, and China reincorporated it in 1950.

In a direct reference to the possibility of war, China's Ambassador to the US suggested that the nations may face a "military conflict" over the future of Taiwan.

According to officials, Taiwan has begun deporting Chinese individuals for the first time in more than a year, despite China's repatriation of a Taiwanese fugitive in a rare show of cooperation as tensions escalate.