A senior official from the department said on condition of anonymity that China would remain engaged in the six nation attempt to solve the North Korea standoff and the so-called "P5+1" group negotiating with Iran.
"In terms of the P5+1, in terms of the Six Party talks, the Chinese are still going to engage very actively on that," the official told reporters. "They made that clear to us."
The official added: "Obviously, they are not happy about this arm package going forward and they want to show their displeasure."
On Friday last week, the Pentagon notified Congress of 6.5 billion dollars in proposed arms sales to Taiwan, including advanced Patriot missile defense systems, Apache attack helicopters and submarine-launched anti-ship missiles.
China has curtailed military exchanges with the United States in response to the sales and has said the plan threatens peace in its region.
The US official said several visits by Chinese warships to the United States had been cancelled and an unnamed Chinese general had also pulled out of a trip to the country.
"That is a way of showing displeasure without obviously cutting off important discussions that we need to have on crucial international issues," said the official.
"And there may be some other (nuclear) non-proliferation discussions where the Chinese have decided not to participate."
Taiwan and the Chinese mainland have been governed separately since they split in 1949 at the end of a civil war, but Beijing sees the island as part of its territory that is awaiting reunification, by force if necessary.
