The U.S. government announced a $1.8 billion arms sale to Taiwan on Wednesday that, if approved by Congress, would send high-profile defense items such as warships and surface-to-air missiles to help bolster the small island nation’s military.

The sale is the first offered to Taiwan in four years and includes $375 million worth of Amphibious Assault Vehicles and two decommissioned Navy Perry-class frigates worth $190 million. Additional items include Javelin antitank missiles, 250 FIM-92 Stinger man-portable air defense systems (MANPADS), and an assortment of other weapons, including CIWS (“sea-whiz”) anti-ship missile defense systems.

In addition to the lethal hardware, the sale also includes a number of data-link systems that will allow for intelligence sharing among Taiwanese forces.

The Chinese government, which has long known about the sale since it was approved more than a year ago, has consistently voiced concerns about Taiwan’s purchase of U.S. arms.

“Taiwan is an inalienable part of China’s territory,” the Chinese vice foreign minister, Zheng Zeguang, said  Wednesday, according to Xinhua News Agency. “China strongly opposes the U.S. arms sale to Taiwan.”

He also said the arms sale violates international law and harms China’s sovereignty and security interests.

“To safeguard our national interests, China has decided to take necessary measures, including imposing sanctions against the companies involved in the arms sale,” Zheng said. “No one can shake the firm will of the Chinese government and people to defend their national sovereignty and territorial integrity, and to oppose foreign interference.”

Dave McKeeby, a State Department spokesman, said the sale is consistent with the United States’ support for Taiwan to defend itself under the Taiwan Relations Act and is consistent with Taiwan’s defense needs.

While Congress has 30 days to approve the sale, lawmakers from both sides of the aisle have already come out in favor of the transfer. Sen. John McCain (R-Az.), chairman of the Senate Armed Services Committee, lauded the deal and in an emailed statement called for the regularization of arms shipments to Taiwan.

Rep. Eliot L. Engel (D-N.Y.), ranking of member of the House Committee on Foreign Relations, also called for a more regular process of sending arms to Taiwan.

“We cannot allow our relationship with the People’s Republic of China to come at the expense of our friendship with the people of Taiwan or our commitment to Taiwan’s defense,” Engel said in an emailed statement.

The last major arms sale to Taiwan was in 2011 and included more than $5 billion in upgrade kits for Taiwan’s aging fleet of F-16 fighters. Although the sale angered China, the repercussions were minimal and involved the cessation of some military-to-military communication.

While there has been a spat of activity in the South China Sea, Taiwan has been relatively removed from any recent entanglements with China. Taiwan-China relations have been on the mend, but China has long stated it will never recognize Taiwan as an independent country.

Dan Lamothe and Carol Morello contributed reporting.