China "firmly opposes this," Hua said, demanding that the US refrain from selling the fighter jets and stop military contact with Taiwan.

"It must be stressed that the Taiwan issue concerns China's sovereignty, territorial integrity and security interests," Hua said and added a warning. The "US will have to bear all the consequences" if it does not stop the arms sales, she said.

The deal received strong bipartisan backing from Congress, including from the Democratic chairman and the leading Republican on the House Foreign Affairs Committee.

"The sale of F-16s to Taiwan sends a strong message about the US commitment to security and democracy in the Indo-Pacific," Democratic Rep. Eliot Engel of New York and Republican Rep. Michael McCaul of Texas said in a joint statement last week.

As China "steps up its military aggression in the region, we need to do all we can to support our friends around the world," they said, adding they "have every confidence that it will be supported on a bipartisan and bicameral basis."

The fighter jets are seen as particularly irksome to Beijing as they would enhance Taipei's ability to potentially conduct military operations in the Taiwan Strait, the narrow waterway that separates China from Taiwan.

Last month, the Trump administration approved selling 108 M1A2T Abrams tanks and portable Stinger anti-aircraft missiles to Taiwan, an arms package valued at $2.2 billion.

Both types of equipment had been requested by Taiwan, which has moved to boost its defense spending as it faces increasing pressure from Beijing in the form of ramped-up military drills and efforts to strip Taipei of its remaining diplomatic allies.

A Pentagon report in May warned that Taiwan's traditional military advantages over Beijing in the event of a cross-strait conflict were eroding in the face of China's military modernization efforts.

Since 2010, the US has announced more than $15 billion in arms sales to Taiwan.