UNITED NATIONS -- Secretary-General Ban Ki-moon said Thursday the crisis in Syria is getting worse and claiming more lives every day even though President Bashar Assad's government insists it is withdrawing troops ahead of a U.N. deadline to end the violence.
The U.N. chief appealed to Assad "to show vision and leadership" and keep his pledge to pull troops and heavy weapons out of cities and towns by Tuesday, and he urged the opposition to be ready to stop all violence if the Syrian government meets the deadline.
"Cities, towns and villages have been turned into war zones. The sources of violence are proliferating," Ban told the U.N. General Assembly. "The human rights of the Syrian people continue to be violated. ... Humanitarian needs are growing dramatically."
His comments came as activists reported that Syrian troops attacked the Damascus suburb of Douma, an assault they said shows that Assad is intensifying violence in the days before the April 10 deadline. His crackdown on the yearlong uprising has left at least 9,000 people dead, according to the U.N.
Earlier Thursday, a U.N. team arrived in Damascus to negotiate the possible deployment of U.N. monitors for any cease-fire between Syrian troops and rebel forces.
Kofi Annan, the U.N.-Arab League envoy trying to end the conflict, said Syria has informed him of partial withdrawals from three locations -- Idlib, Zabadani and Daraa -- "but it is clear that more far-reaching action is urgently required."
Annan and Ban spoke to the General Assembly minutes after the U.N. Security Council called on Syria to "urgently and visibly" fulfill its pledge to halt the use of troops and weapons by April 10. It raised the possibility of "further steps" if Syria doesn't implement the six-point peace plan outlined by Annan, which Assad agreed to March 25.
"All points of the plan are crucial, but one is most urgent: the need for a cessation of violence," Annan told diplomats from the 193 U.N. member states by videoconference from Geneva. "Clearly, the violence is still continuing. Alarming levels of casualties and other abuses continue to be reported daily. Military operations in civilian population centers have not stopped."
Ban said despite the Syrian government's acceptance of Annan's plan, "the violence and assaults in civilian areas have not stopped."
"The situation on the ground continues to deteriorate," he said.
The secretary-general has been speaking out against the violence in Syria for many months, but his remarks Thursday were especially strong and highly critical of the Assad government for unleashing attacks in the first place in response to "the legitimate demands of the Syrian people -- the same demands that people across the Arab world have been making for more than a year now."
Syria's U.N. Ambassador Bashar Ja'afari confirmed that hostilities have escalated in some "hotspots" where he said armed groups have "jumped to fill the vacuum" when they heard that the Syrian government withdrew some military units.
He reiterated the government's commitment to "the success" of Annan's six-point plan and said all heavy weapons would be withdrawn by April 10. But he also appeared to put at least one condition on the pullout of Syrian troops from cities and towns.
Ja'afari accused Qatar, Saudi Arabia, Turkey, France and the United States of assisting the Free Syrian Army and said his government needs "a crystal cut commitment and a guarantee by Mr. Annan himself after he consults with Saudi Arabia, Turkey and the others that once the government will observe and will respect the end of violence, the other parties will do the same and not fill the vacuum."
He said obtaining the guarantee before the April 10 deadline for the pullout "is an integral part of the common understanding between Mr. Kofi Annan and the Syrian government." He added that Syria needs "a written commitment from everybody including the imam of Saudi Arabia."
Ja'afari called the news conference late Thursday to attack General Assembly President Nassir Abdulaziz Al-Nasser, who is from Qatar, for refusing to allow him to present Syria's position at the General Assembly or to call for a one-minute silence to honor all those who've died in the Syrian conflict.
Annan said all opposition parties his team has talked to "are committed to call for cessation of violence once the Syrian government has demonstrably fulfilled its commitments regarding use of heavy weapons and troop withdrawals."
In planning for a possible cease-fire, a team led by Norwegian Maj. Gen. Robert Mood arrived Thursday in Damascus to begin discussing with the Syrian authorities "the eventual deployment of this U.N. supervision and monitoring mission," Annan's spokesman Ahmad Fawzi said.
He said the U.N. is looking for a team of 200 to 250 soldiers to monitor a cease-fire.
The deployment of U.N. monitors would first have to be authorized by the 15-nation Security Council.
While a halt to violence is a beginning, Annan stressed the importance of moving forward quickly on a Syrian-led political process including all parties to restore peace and "meet the aspirations of the Syrian people."
Annan has courted support for his six-point peace plan at meetings with leaders in Moscow and Beijing and now plans to visit Tehran on April 11, Fawzi said.
Russia and China have vetoed two Security Council resolutions condemning Assad's regime for the crackdown on protesters, and have ruled out any mention of possible sanctions against Syria.
Diplomats said Thursday's presidential statement was watered down at the insistence of Russia and China from a "demand" to a "call" on Syria to implement the April 10 deadline.
They also insisted that the word "verifiably" be changed to "visibly," the diplomats said, speaking on condition of anonymity because negotiations were private.
French Foreign Minister Alain Juppe said he was not optimistic about a peace plan for Syria and is ready to push for stronger U.N. action if the deadline is not met. Assad "is deceiving us" when he promises to abide by the peace plan, Juppe said.
"If we manage to get 200 observers (and the other measures in the peace plan) in place, things will change dramatically," he told reporters in Paris. "If we don't manage to get this by April 12, we have to go back to the U.N. Security Council."
Syria's key ally Russia, has grown increasingly impatient with Assad, criticizing him for being slow at reforms and urging him to take the first step in implementing Annan's plan.
But Russia has vowed to block any U.N. resolution that could pave the way for a replay of what happened in Libya, where NATO action helped oust longtime dictator Moammar Gadhafi.
John Heilprin reported from Geneva. Michael Astor contributed to this report from the United Nations and Angela Charlton from Paris.