The US' tacit support to Taiwan and arms supply to the self-ruled island irks Beijing and the latest report about Washington planning a $2 billion weapons sale to Taipei will add to the raging Sino-American trade tensions.
"We are seriously concerned about the US move. We are firmly against the US' arms sale to Taiwan... Our position is clear and consistent," said Chinese Foreign Ministry spokesperson Geng Shuang.
According to a news report, the US was planning to sell anti-tank, anti-aircraft weapons among others worth $2 billion to Taiwan, a self-governed island which China claims as its own and vows to reunite with the mainland someday.
"We urge the US to see high sensitivity and severe harm in selling arms to Taiwan, abide by the One-China principle and three joint communiques, stop arms sales to Taiwan as well as cut off its military ties with Taiwan," Geng said.
"We also urge the US to prudently deal with issues related to Taiwan to prevent harm to bilateral relations and peace and stability in the Taiwan Strait."
Even if the US severed its diplomatic channels with Taiwan in 1979 and established ties with China, it is bound by law to sell arms to Taipei for its defence.
This has long been a sore point in Washington-Beijing ties and become more contentious after US President Donald Trump came to power.
After taking office in 2016, Trump spoke to Taiwan's President Tsai Ing-wen by the phone, breaking an almost four-decade protocol that rattled China.
( With inputs from IANS )