The United States is required by law to supply Taiwan, which has a democratically elected president and legislature, with weapons for its defence under the 1979 Taiwan Relations Act.
US President Donald Trump offered to sell arms to Beijing in response to concerns over weapons sales to Taiwan, the US ambassador to China said in a Fox News interview that aired on Sunday.
China claims Taiwan is part of its territory and US arms sales to the self-ruled island have long been a thorny issue between Washington and Beijing.
The United States is required by law to supply Taiwan, which has a democratically elected president and legislature, with weapons for its defence under the 1979 Taiwan Relations Act.
US Ambassador to China David Perdue said the issue was raised again when Chinese President Xi Jinping visited the United States last week.
"President Trump continues to say, 'Hey, we sell arms to other people around the world.' He actually asked President Xi would he like to buy some at one point," Perdue said in the interview that aired on Sunday.
"There are continuing conversations about other sales, (Trump) and President Xi talk about that every time they get together," Perdue said, adding the US position has not changed.
In June, China warned Taiwan that seeking independence "by relying on the United States or through military means is a dead end."
Washington had already approved a $11.1 billion (€9.7 billion) arms sale to Taiwan in December, which Perdue said was a sale of "more arms to Taiwan than any other president since 1979."
During his Washington trip, Xi repeated his warning that Trump should show "prudence" over Taiwan, and went further to urge the United States to oppose Taiwan independence explicitly.
In May, Trump suggested an upcoming arms package to Taipei could be used as a negotiating chip with China, raising fears Taiwan's security could be traded away.