BEIJING, Sept 24 (Reuter) - Beijing on Sunday condemned what it called Washington's covert connivance with China's enemies, branding U.S. President Bill Clinton's recent meeting with Tibet's exiled Dalai Lama a "grave act of deliberate interference."

The official Xinhua news agency, in a signed commentary published in its Xinhua Daily Telegraph, said the September 13 meeting between Clinton and the Dalai Lama was a troubling new affront that raised questions about Washington's sincerity.

Xinhua called the White House meeting with the Buddhist spiritual leader "another grave act of deliberate interference in China's internal affairs" following a visit to the United States by President Lee Teng-hui of Taiwan, China's arch rival.

"Soon after the 'Taiwan card,' it played the 'Tibet card,' inflicting new injuries to (Sino-U.S.) relations while the old wounds have not healed," Xinhua commentator Ji Yan wrote.

"What the U.S. government has done makes one wonder whether it has any sincerity in its claim to improve the Sino-U.S. relations.

Xinhua rejected U.S. assertions that Clinton had merely dropped in on a meeting between the Dalai Lama and Vice President Al Gore, calling this further evidence of U.S. connivance with what Beijing has labelled an independence-seeking "splittist."

"To describe the Clinton-Dalai Lama meeting as an incidental event is nothing but Washington's diplomatic rhetoric to gloss over its connivance at the Dalai Lama's activity to split China," it said.

China withdrew its U.S. ambassador after Lee Teng-hui's June trip to New York state for a Cornell University reunion, a visit described as private and unofficial.

China regards Taiwan and Tibet as its sovereign territory and regularly reminds Washington it accepted this policy in three joint communiques that enabled the establishment of Sino-U.S. diplomatic ties in 1979. Xinhua said the new frictions over Taiwan and Tibet showed the United States was trying to create "two Chinas" or "one China, one Taiwan" and supporting Tibetan independence.

"Time and again Washington has publicly admitted that Tibet is part of China and declared that it will not recognize an independent Tibet or Tibet as a sovereign state, nor the Dalai Lama's 'government'in exile," the commentary said.

"But covertly the U.S. government and the Congress have been backing the separatist activity of the Dalai Lama for a long time," it said. Clinton also met the Dalai Lama in 1993 and 1994. Taiwan has been ruled since 1949 by the Chinese Nationalist government that was defeated by the communists on the mainland in the Chinese civil war. Beijing regards it as a renegade province and has said it would not rule out military force to prevent it from seeking independence.