UN Secretary-General Ban Ki-moon says Syria had not fully complied with its obligations to withdraw troops and heavy weapons from flashpoint towns and cities in Syria.
Ban, who made the assessment in a letter addressed to the UN Security Council, said the Syrian government had yet to send a “clear signal" about its commitment to peace.
In the same letter, the UN chief also recommended the UN increase the number of observers it has sent to monitor the fragile week-old cease-fire in Syria to 300, insisting that the current team of 250 was insufficient.
Syrian Foreign Minister Walid Muallem had previously rejected proposals to expand the number of monitors, saying that 250 is a "reasonable and logical" number of observers to monitor the cease-fire.
In Paris, foreign ministers of the group Friends of Syria are expected to meet on Thursday to discuss the shaky cease-fire between forces loyal to President Bashar Assad and opposition fighters seeking to oust him.
U.S. Secretary of State Hillary Clinton, who is due to attend the Paris meeting, has warned Assad will face tougher penalties if he squanders his "last chance" to implement the peace plan put together by UN-Arab League envoy Kofi Annan and backed by the international community.
"We are at a crucial turning point," Clinton said. "Either we succeed in pushing forward with Kofi Annan's plan in accordance with the Security Council direction, with the help of monitors, steadily broadening and deepening a zone of nonconflict and peace, or we see Assad squandering his last chance before additional measures have to be considered."
Russia said on April 19 it was not attending the meeting in Paris because the talks were only intended to marginalize the Syrian regime and would harm the chances of direct peace talks.
A six-member advance team of UN monitors arrived in Syria over the weekend to begin monitoring the situation and negotiate with Syrian authorities, but the head of the team, Colonel Ahmad Himmiche, admitted that his team faced many challenges.
"Our mission is to establish liaison with the Syrian security forces and also with other parties," Himmiche said. "To establish this liaison, we need time, we need trust, we need to build confidence and trust within all the parties in order to achieve our task."
On April 18, gunfire broke out when the UN monitors visited a suburb of the capital Damascus where they were mobbed by anti-Assad demonstrators. There were no reports of casualties.
Based on reporting by Reuters, AP, and AFP