More than 130 athletes are imploring China, America, and other nations to make the Olympic truce a reality by bringing violence in Sudan’s Darfur region to a halt while the Summer Games are under way in Beijing.

“The idea of the Olympics as a force for peace has a long history,” a speed skater who won gold and silver medals for America in 2006 and a bronze in 2002, William Cheek, told a news conference in Washington yesterday. “No one throughout the world doubts that sport can act as a unifier, a force for peace, and bring governments and people together in ways that might otherwise not be possible.”

Groups working to end the genocide in Darfur released a letter in which Mr. Cheek and other Olympians and Olympic hopefuls from across the globe pleaded for action to resolve the crisis in Sudan. “There could be no greater example of the Olympic ideal of promoting peace through sport than for the international community to use the 2008 Olympic truce to end the first genocide of the 21st century,” the athletes wrote in their missive to President Bush, President Hu, and other world leaders, including the president of the International Olympic Committee, Jacques Rogge.

“What we’re asking for is 55 days of peace,” a member of the American softball team for the 2008 games in Beijing, Jessica Mendoza, said during the news briefing, monitored in a conference call arranged by the Darfur activists.

In April, a U.N. official estimated that 300,000 people have been killed in Darfur, mostly by tribal militias backed by and often working in concert with the Sudanese regime.

Mr. Cheek said he and other athletes view violence like that in Darfur as a jarring counterpoint to the Olympic Games. “On the very day that I was competing, it was most likely that people died, people were gunned down in their homes, people were driven from their homes and left for dead,” the skater said. “As now, that notion offended me.”

The concept of the Olympic truce can be traced back to the origins of the games in ancient Greece, where warring factions suspended hostilities to allow athletes and observers safe passage. It was resurrected in modern times in 1956 during the Hungarian uprising.

Mr. Cheek noted that the Olympic truce was observed in 1996 in fighting taking place between the Sudanese government and the Sudanese People’s Liberation Army. “In that region, there is a precedent for an Olympic truce to be used successfully to help innocents and victims of war,” he said.

Advocates for the truce are lobbying a variety of countries but are putting a special emphasis on China, which is the host nation for the Summer Games and which has close ties to the Sudanese government. The athletes’ plea was released as the U.N. secretary-general, Ban Ki-moon, arrived in Beijing for talks with Chinese leaders.

“It seems China is either unwilling or unable to use its influence to stop the Darfur genocide,” Jill Savitt of Dream for Darfur said. “This could at long last be the show of political will by the international community to stand up to Khartoum.”