The Chicago Tribune journalist, who was freed along with his Chadian driver and interpreter, said during a brief news conference in this Sudanese capital that his "treatment was excellent."
Salopek, 44, was on assignment for National Geographic magazine when he was arrested last month and accused of passing information illegally, writing "false news" and entering the African country without a visa.
Bill Richardson, the governor of the U.S. state of New Mexico, traveled to Sudan on Friday to meet with President Omar al-Bashir and persuaded him to release Salopek and his colleagues.
"It was a humanitarian gesture," Richardson said Saturday during the news conference at a hotel. "All the problems can always be solved through negotiations."
Salopek's wife, Linda Lynch, and Chicago Tribune Editor Ann Marie Lipinski and Chris Johns, National Geographic magazine's editor and chief, traveled with Richardson from Khartoum to Darfur on Saturday to pick up Salopek and his assistants.
"I am now happy for having Paul released, that we have reunited. I am also grateful for President al-Bashir and Governor Richardson and all the people who helped in the release of Paul," Lynch said Saturday.
A judge in the North Darfur capital of el-Fasher released Salopek and his assistants after a 13-minute hearing earlier Saturday.
"We are stopping the case and we are releasing you right now. And that is all," the judge said in English, according to a story published Saturday on the Chicago Tribune's Web site.
The journalist was scheduled to return to New Mexico, where he has a home, as early as Sunday, and his two assistants were to go to Chad, the Tribune reported.
"Everybody is absolutely delighted. I've worked for 20 years in Africa and never had a better day than this one," National Geographic's Johns told the Tribune.
Richardson, a former congressman, U.N. ambassador and energy secretary during the Clinton administration, helped in 1996 to get three Red Cross workers, including an Albuquerque pilot, released from Marxist rebels in Sudan.
"We have been friends for the last 10 years and this relationship has helped a great deal in my job of urging them to release the journalist and his colleagues," Richardson said.
In 2001, Salopek won a Pulitzer for international reporting for his work covering Africa. In 1998, he won a Pulitzer for explanatory reporting for his coverage of the Human Genome Diversity Project. At the time of his arrest, he was working on an article about the people, culture and history of the sub-Saharan region known as the Sahel.