French President Nicolas Sarkozy says he has not ruled out boycotting the opening ceremony of the Olympic Games in China over the situation in Tibet.
His aides said France was still opposed to a full boycott but that it might pull out of the opening ceremony in Beijing on 8 August.
The recent unrest in Tibet has sparked worldwide concern.
Olympics chief Jacques Rogge said last week he was "heartened" that no major government had backed a boycott.
On Tuesday, the White House said US President George W Bush still planned to attend the opening of the Games, while the UK said Prime Minister Gordon Brown would still be going to the closing ceremony.
When asked about a possible boycott on a visit to the south-western Pyrenees region, Mr Sarkozy said: "All options are open and I appeal to the Chinese leaders' sense of responsibility."
He added: "I want a dialogue to start and I will step up my response according to the response given by the Chinese authorities."
Activists disrupted the Olympic torch lighting ceremony in Greece
France's state TV network said it might boycott coverage of the Games if Beijing censored protests during the event.
In Washington, White House spokeswoman Dana Perino said: "Our position remains that we believe that the purpose of the Olympics is to let international athletes come together and showcase their talents."
France and other Western nations have urged Beijing to enter into a dialogue with the exiled Tibetan spiritual leader, the Dalai Lama.
China says 19 people were killed by rioters and accuses the Dalai Lama of inciting the violence.
The Tibetan government-in-exile says at least 130 people have died in a crackdown by Chinese troops and deny any role in the protests.
Robert Menard, the director of the media rights group Reporters Without Borders, said he had asked Mr Sarkozy for a meeting where he will press for a boycott of the opening ceremony, though not a boycott of sports events.
On Monday, pro-Tibetan activists disrupted the Olympic torch lighting ceremony in Greece.
Campaigners broke through police lines and unfurled a Tibetan flag before being dragged away.
In his speech during the ceremony, Mr Rogge said the Olympic torch relay and the Games should take place in a peaceful environment.
On Tuesday, the Chinese foreign ministry said any attempt to disrupt the torch relay for the Olympic Games was shameful.