Chinese Foreign Minister Yang Jiechi said on Sunday that relations with the United States had been seriously disrupted, after a rise in friction between the two big powers.

The responsibility does not lie with China, said Yang, speaking at a news conference on the sidelines of the annual session of China's parliament.

Beijing and Washington have recently gone through a rough patch, with quarrels in January and February over Chinese Internet censorship, trade disputes, U.S. arms sales to Taiwan, and President Barack Obama's meeting with the Dalai Lama, the exiled Tibetan leader.

The United States must respect China's core interests on Taiwan and Tibet, Yang added. I believe the United States understands very well China's core interests and major concerns.

China has always attached importance to its relationship with the United States, he said. Resolutely adhering to one's principled stance is not the same thing as being hardline.

But the two big trade partners appear to want to lower the temperature of the disputes as they also grapple with how to deal with how to deal with Iran and North Korea.

Beijing has not yet acted on its threat to sanction U.S. companies involved in the arms sales to Taiwan, the self-ruled island that Beijing claims as part of its territory.

Last weekend, Chinese Premier Wen Jiabao said he wanted trade friction with the United States to ease.

(Reporting by Chris Buckley; Writing by Ben Blanchard; Editing by Bill Tarrant)