Dutch Foreign Minister Bernard Bot, whose country holds the EU's rotating presidency, told his European counterparts on Monday that Khartoum had to prove "it wants to stop the bloodletting and the fighting".
The rebellion in the western region of the country has led to a brutal backlash by pro-government militias.
"We are waiting for the signals in the coming days and in the light of the situation we will then consider whether we will have to increase pressure on the government and impose sanctions," he said following a meeting of foreign ministers in Brussels.
Bot called for a "carrot-and-stick" approach to the crisis, combining humanitarian aide and political pressure on Khartoum.
He said the EU, the US and the UN should "make crystal clear to the Sudanese government that it cannot escape its responsibility..."
Chance for political solution
In a joint declaration, the EU foreign ministers called on "all parties, including the rebels, to engage, in good faith, in negotiations promoted by the African Union (AU)" starting with a meeting planned for 15 July in Addis Ababa.
More than 10,000 people are estimated to have died in Darfur and at least 1.2 million have been driven from their homes, many of them to squalid camps in Chad, since a revolt against the government broke out in February 2003.
Pro-government militias in turn have carried out what UN officials claim is a campaign of ethnic cleansing.
Sudanese President Umar al-Bashir has pledged to crack down on the so-called Janjawid militias and help protect destitute villagers, but fighting has continued.