The United States has approved a possible $100 million sale of equipment and services to Taiwan to “sustain, maintain, and improve” the Patriot missile defense system, the Pentagon said on Monday.

A statement from the U.S. Defense Security Cooperation Agency said it had delivered the required certification notifying Congress following State Department approval for the sale, which was requested by Taiwan’s de facto embassy in Washington.

Upgrades to the Patriot Air Defense System would “help improve the security of the recipient and assist in maintaining political stability, military balance, economic and progress in the region,” the DSCA said in a statement.

The proposed sale serves U.S. national, economic, and security interests by supporting the recipient’s continuing efforts to modernize its armed forces and to maintain a credible defensive capability, the agency said.

The main contractors would be Raytheon Technologies and Lockheed Martin, it said.

Taiwan’s Foreign Ministry said it “highly welcomed” the decision.

In the face of China’s continued military expansion and provocative actions, our country will maintain its national security with a solid defense, and continue to deepen the close security partnership between Taiwan and the United States, the author of the statement said.

Taiwan’s Defense Ministry has said the decision to obtain newer Patriot missiles was made during a 2019 meeting with U.S. officials in the administration of President Donald Trump.