TIMELINE: Relations between China and the United States

(Reuters) - U.S. President Barack Obama is in China, seeking to draw the two big powers closer. Here is a timeline of U.S.-Chinese relations since 1949:

October 1949 - People's Republic of China founded by the Chinese Communist Party. The United States keeps diplomatic ties with defeated Nationalist forces who fled to Taiwan, claiming their Republic of China as the sole legitimate government. 1950 - Korean War breaks out with the United States and China sending forces to support rival sides in fighting that lasts until 1953.

1958 - China shells islands between the mainland and Taiwan, held by Nationalist forces, escalating tensions with the United States, which maintains forces on Taiwan.

1960s - United States pursues deepening military involvement in Vietnam, while China more quietly backs Vietnamese Communist forces fighting the U.S.-backed government in the south.

1969-1970 - Secretive and long-moribund back-channel contacts between China and the United States resume as President Richard Nixon and Mao Zedong explore ways to improve relations.

April 1971 - "Ping-pong diplomacy" when China invites U.S. table tennis players to visit, generating a burst of goodwill.

1971 - Nixon's national security advisor, Henry Kissinger, visits China twice, secretly in July and openly in October.

February 1972 - President Richard Nixon visits China, meets ailing Chairman Mao and Premier Zhou Enlai and both sides set out principles for relations between the two nations.

January 1979 - China and the United States establish diplomatic relations after the United States breaks diplomatic ties with Taiwan.

January-February 1979 - Deng Xiaoping, the Communist Party veteran guiding China's steps toward economic reform, visits the United States. Deng is struck by the economic and technological gap between his country and America.

April 1979 - The United States enacts the Taiwan Relations Act, which spells out U.S. obligations to help Taiwan defend itself against possible military threats from China.

June 1989 - Ties dive after Deng uses troops to suppress pro-democracy protesters in Beijing. President George H.W. Bush later authorizes sanctions but seeks to maintain communication and limit fallout.

June 1995 - President Bill Clinton allows Taiwan's President Lee Teng-hui to visit United States, drawing harsh denunciations from China.

1995-1996 - China shows its anger with Lee's visit by holding missile tests near Taiwan. In 1996, China resumes the missile tests before Taiwan's presidential election, unsuccessfully seeking to deter voters from backing Lee. Washington sends aircraft carriers and other naval ships to the area.

May 1999 - U.S. planes in NATO's offensive against Yugoslavia bomb the Chinese embassy in Belgrade, killing three Chinese nationals, unleashing protests outside the U.S. embassy in Beijing. China says the bombing was intentional. The United States says it was a mistake.

May 2000 - United States grants China "Permanent Normal Trade Relations" (PNTR) status, opening the way for China to join the World Trade Organization in 2001.

April 2001 - A U.S. surveillance plane collides in mid-air with a Chinese air force plane near the southern Chinese island of Hainan, leading the Chinese plane to crash into the sea and forcing the U.S. aircraft to land on Hainan. An 11-day standoff over China's holding of the plane and 24 crew members raises tensions with the new administration of President George W. Bush.

September 2001 - China voices support for the United States after the September 11 attacks, opening the way to improved ties with the Bush administration.

August 2003 - Beijing hosts the first round of six-party talks seeking to end North Korea's nuclear weapons program. The talks open a new forum for cooperation between China and the United States, which participates in the talks.

September 2008 - China passes Japan as the biggest holder of U.S. government debt, and the deepening global financial crisis magnifies the importance of Chinese economic ties for President Barack Obama, who takes office in January 2009.