US-China tensions hang over talks
Disputes over an incident at sea and the issue of Tibet are threatening to overshadow talks in Washington between top US and Chinese diplomats.
US Secretary of State Hillary Clinton meets counterpart Yang Jiechi later for talks aimed at paving the way for a presidential meeting next month.
But a confrontation at the weekend in the South China Sea has caused both sides to issue complaints.
Beijing has also criticised a US statement on the issue of Tibet.
The two foreign ministers are to have lunch in the US capital, and Mr Yang will also meet Treasury Secretary Tim Geithner.
Correspondents say Mrs Clinton and Mr Yang will try to tone down the disputes and build on the goodwill from Mrs Clinton's recent visit to Beijing.
Ahead of the talks, China heaped criticism on the US after Sunday's maritime incident.
The Pentagon said five Chinese ships harassed an unarmed US navy surveillance vessel in a dangerous manner while it was on routine operations in international waters 75 miles (120km) south of Hainan island.
See map showing rival claims in the South China Sea
But China called the US complaint "totally inaccurate" and accused it of breaking international law by operating in its Exclusive Economic Zone (EEZ).
Territorial claims from China, the Philippines, Taiwan, Brunei, Vietnam and Malaysia overlap in resource-rich sea
Hosts some of the world's busiest shipping lanes
China says the US was in its Exclusive Economic Zone - but the two sides disagree on what activities are allowed in an EEZ
The US ship had behaved "like a spy" and China's action was "totally within our rights", state media quoted senior naval officials as saying.
"What was the ship doing? Anyone with eyes can see and our navy can see even more clearly," the China Daily quoted Vice Admiral Jin Mao, former vice-commander of the navy, as saying.
"It's like a man with a criminal record wandering just outside the gate of a family home. When the host comes out to find out what he is doing there, the man complains that the host had violated his rights."
The boundaries of China's EEZ remain disputed, while Beijing and Washington differ on which activities are permitted by law within a nation's EEZ. China has a key submarine base on Hainan island.
There are also tensions over Tibet, in the wake of Tuesday's 50th anniversary of the uprising in Lhasa that forced the Dalai Lama into exile.
In a statement, the US State Department said it was "deeply concerned" about the human rights situation in Tibet.
"We urge China to reconsider its policies in Tibet that have created tensions due to their harmful impact on Tibetan religion, culture, and livelihoods."
China said that the US had confused the facts.
The US had "wrongly accused China for no reason with its gross interference in Chinese internal affairs," Foreign Ministry spokesman Ma Zhaoxu said in a statement.
The US and Chinese foreign ministers first met in Beijing last month
SOUTH CHINA SEA TENSIONS