"The next months will be important in showing if the extra personnel that the mission requires can lower insecurity and improve the political situation," General Delauney, part of a European group advising the African Union, told the foreign minister.
The African Union ambassador in Darfur, Burkinabe's Jean-Baptiste Natama, said the peacekeeping force would need to be increased from 4,000 to 7,000 by the end of August, but the union lacked the resources.
France has so far funnelled 80 million euros (96 million dollars) to Darfur through the African Union.
Douste-Blazy later travelled by muddy tracks to the world's largest refugee camp, Kalma, which houses 100,000 people and is 13 kilometres (8 miles) long and 5 kilometres (3 miles) wide.
A humanitarian worker at the Kalma camp, which houses various ethnic groups and was the scene of riots in May, said lawlessness was a greater problem than food supplies and health.
"The situation is very tense and the refugees can't go more than a kilometre from the camp without the risk of falling victim to robberies and rape, in the case of women, particularly by the Sudanese police," he said.
The war between rebels and government forces supported by Jenjaweed Arab militias has claimed up to 300,000 lives and displaced 2.4 million people, sparking a humanitarian crisis in neighbouring Chad.
Following the US Secretary of State Condoleeza Rice's visit to Sudan on July 21, the Sudanese government called for negotiations under the auspices of the African Union to be brought forward.
A ceasefire agreed in April 2004 had been generally respected in recent months despite sporadic outbreaks, peacekeepers said.