Syrian President Bashar al-Assad has told UN Secretary-General Ban Ki-moon that military and police operations against pro-democracy protesters have stopped, the United Nations said.

The announcement came as the Obama administration was expected to call on Assad to step down, sources speaking on condition of anonymity told Reuters. It could come as soon as Thursday, August 18, with the European Union expected to follow suit, the sources said.

In a phone call with the Syrian leader on Wednesday, Ban "expressed alarm at the latest reports of continued widespread violations of human rights and excessive use of force by Syrian security forces against civilians across Syria, including in the Al Ramel district of Latakia, home to several thousands of Palestinian refugees," the UN said in a statement released late on Wednesday.

"The Secretary-General emphasized that all military operations and mass arrests must cease immediately. President Assad said that the military and police operations had stopped," the statement added, Reuters reported.

The government crackdown is estimated to have killed at least 2,000 civilians since the protests began five months ago.

The U.N. human rights chief also is expected to suggest that the U.N. Security Council refer Syria's crackdown on pro-democracy protesters to the International Criminal Court, envoys said.

The developments were part of a flurry of diplomatic maneuvers ramping up the pressure on Assad to stop his military and police crackdown on protesters against his rule.