Taiwan will buy three advanced weapons systems to deter a cross-strait amphibious invasion by mainland China, the U.S. says.

The U.S. government told Congress it would sell these weapons to Taiwan. The sale of weapons from the U.S. to Taiwan this year has added to tensions between Taiwan and China.

Taiwan has said war is possible if China keeps allegedly violating its territory with unauthorized flights into its aerial defense identification zone and naval intrusions along its southwestern coast.

Taiwan this year has boosted its purchases of U.S. military equipment in a bid to transform itself into a "military porcupine."

Late last week, U.S. national security adviser Robert O'Brien encouraged Taiwan to spend more on its own defense and implement military reforms to make clear to China the risks of an invasion.

"You can't just spend 1% of your gross domestic product, which the Taiwanese have been doing - 1.2% - on defense, and hope to deter a China that's been engaged in the most massive military buildup in 70 years," O'Brien said. Taiwan has to "turn themselves into a porcupine" militarily. "Lions generally don't like to eat porcupines," he said.

O'Brien said Taiwan had to buy more cruise missiles for coastal defense, naval mines, fast-attack boats, mobile artillery and advanced aerial surveillance.