U.N. Secretary General Ban Ki-moon has urged Syrian President Bashar al-Assad to stop the use of force against civilians "immediately".

In a telephone conversation on Saturday, Ban spoke to the Syrian leader to express "his strong concern and that of the international community at the mounting violence and death toll" in Syria over the past week, the U.N. press office said in a statement.

"He reflected to the Syrian President the clear message sent by the Security Council and urged the President to stop the use of military force against civilians immediately," added the U.N. statement.

Ban also asked President Assad to stop the mass arrests of protestors.

President Assad is drawing a lot of flak from the international community for spurring violence by using troops and tanks to suppress the protests.

Assad referred to the large number of lives lost among security forces and police. Ban responded by saying that he condemned violence against both the civilians as well as security forces.

Ban also told Assad that for the U.N.'s recently announced reform measures to "gain credibility, the use of force and mass arrests must stop immediately," the statement said.

The U.N. leader also made renewed calls for Syria to allow missions from international humanitarian agencies and the UN High Commissioner for Human Rights.

Despite international condemnation, Syrian forces continued with the crack down on protests on Friday.  At least 24 people have been killed on Friday during demonstrations against President Assad's government and at least 200 people have been killed in Hama since last Sunday by security forces. On Saturday, Syrian forces tightened a siege on the city of Hama, the main center of the nearly five-month-old uprising against President Bashar Assad's regime.

On Sunday, activists said the army had launched a pre-dawn assault on the eastern city of Deir ez-Zor, attacking it from four sides and taking control of eight neighborhoods so far, according to an Associated Press report.

London-based Syrian Observatory for Human Rights told AFP news agency that shelling was reported from at least three suburbs reports BBC.  However, this could not be verified added the report.

About 1,650 civilians have been killed and tens of thousands arrested since anti-government demonstrations began in March across many cities in Syria. Protesters have been calling for political reforms and the reinstatement of civil rights, as well as an end to the state of emergency which has been in place since 1963.

As violence continues to escalate, Walid al-Muallem, Syria's foreign minister promised "free and fair" general elections by the end of the year. He said the new parliament will represent the aspirations of the Syrian people.  Shortly after Muallem's announcement, security forces on Saturday arrested Walid al-Bunni, a prominent opposition figure and former political prisoner, the head of the SOHR told AFP news agency.

Turkey, France and Germany have also condemned President Assad's use of force to repress the protests.

Turkish Prime Minister, Recep Tayyip Erdogan said that, "our patience is running out," and that Turkey's Foreign Minister, Ahmet Davutoglu, would visit Syria on Tuesday to hold "necessary talks."

"Our messages will be conveyed to them clearly during this visit and the upcoming process will be shaped according to their response and steps that will be taken," he said.

"I don't believe that Assad has a political future ahead of him which is supported by the Syrian people", German Foreign Minister, Guido Westerwelle told the German Sunday newspaper Allgemeine Sonntagszeitung.