WASHINGTON (Reuters) - China has halted nascent nuclear-arms-control talks with the United States, its foreign ministry said on Wednesday, in a protest of Washington's arms sales to the democratically governed island of Taiwan, which Beijing claims as its territory.

Chinese Foreign Ministry spokesperson Lin Jian said repeated U.S. arms sales to Taiwan in recent months had "seriously compromised the political atmosphere for continuing the arms-control consultations."

"Consequently, the Chinese side has decided to hold off discussion with the U.S. on a new round of consultations on arms control and non-proliferation. The responsibility fully lies with the U.S.," Lin told a regular news briefing in Beijing.

Lin said China was willing to maintain communication on international arms control, but that the U.S. "must respect China's core interests and create necessary conditions for dialogue and exchange."

The U.S. State Department did not respond immediately to a request for comment on the move.

U.S. and Chinese officials resumed nuclear-weapons discussions in November, but formal arms-control negotiations had not been expected any time soon despite U.S. concerns about China's rapid nuclear weapons build-up.

The U.S. estimates China has 500 operational nuclear warheads and will probably have more than 1,000 by 2030.

U.S. officials have expressed frustration that Beijing has showed little interest in discussing steps to reduce nuclear weapons risks. But Beijing has long argued that the U.S. already has a much larger arsenal.

The U.S. has a stockpile of about 3,700 nuclear warheads, of which roughly 1,419 strategic nuclear warheads were deployed. Russia has about 1,550 nuclear weapons deployed and according to the Federation of American Scientists, a stockpile of 4,489 nuclear warheads.

The U.S. is Taiwan's most important international backer and arms supplier even in the absence of formal diplomatic ties. China has repeatedly demanded that these arms sales stop.

Taiwan has protested for the past four years about stepped-up Chinese military activity near the island, including almost daily missions by Chinese warplanes and warships.

(Reporting by Michael Martina and David Brunnstrom; editing by Rod Nickel)