Harpoon missile
© Roslan Rahman / AFP
Harpoon missile launchers on the US Navy USS Coronado (LCS 4) which docked at Changi Naval Base in Singapore on October 2016.
The U.S. State Department has approved the potential sale of 100 Boeing-made Harpoon Coastal Defense Systems to Taiwan in a deal that has a potential value of up to $2.37 billion, the Pentagon said on Monday.

The move comes days after the State Department approved the potential sale of three other weapons systems to Taiwan, including sensors, missiles and artillery that could have a total value of $1.8 billion, prompting a sanctions threat from China.

China will impose sanctions on Lockheed Martin LMT.N, Boeing Defense, Raytheon RTX.N and other U.S. companies it says are involved in Washington's arms sales to Taiwan, a Chinese foreign ministry spokesman said Monday.

"We deplore Beijing's efforts to retaliate against U.S. and foreign companies for their sales that support Taiwan's legitimate self-defense requirements," U.S. State Department spokeswoman Morgan Ortagus said in a statement.

Monday's formal notifications to Congress by the State Department covered the proposed sale of up to 100 Harpoon Coastal Defense Systems (HCDS), which includes 400 RGM-84L-4 Harpoon Block II Surface Launched Missiles to serve as coastal defense cruise missiles.

Taiwan said the arms sales showed the island's defense was of "great importance" to the U.S. government.

"Facing China's military expansion and provocation, Taiwan will continue to enhance the modernization of defense capacity and speed up asymmetric warfare capabilities," it said in a statement.

The State Department sent notifications to Capitol Hill last week for the first tranche of arms sales including truck-based rocket launchers made by Lockheed, Standoff Land Attack Missile Expanded Response (SLAM-ER) missiles and related equipment made by Boeing Co BA.N, and external sensor pods for F-16 jets.

Reuters was first to report in September that sales of major weapons systems to Taiwan were making their way through the U.S. export process.

The formal notification gives Congress 30 days to object to any sales, but this is unlikely given broad bipartisan support for the defense of Taiwan.

The U.S. moves come as the Trump administration ramps up pressure on China in the run-up to the Nov. 3 presidential election and concerns rise about Beijing's intentions toward Taiwan. Beijing sees Taiwan as a breakaway province that it has vowed to "reunite" with the mainland, by force if necessary.