BEIRUT - The Syrian government said it could not be responsible for the safety of international ceasefire monitors unless it is involved in "all steps on the ground", a government spokeswoman and presidential adviser said on Sunday.Bouthaina Shaaban also said Syria, which has lost many former allies during a violent 13-month crackdown against opponents of President Bashar Assad, reserved the right to refuse monitors depending on their nationality."The duration of the work of observers and priorities of their movement will be in coordination with the Syrian government because Syria cannot be responsible for the security of these observers unless it coordinates and participates in all steps on the ground," she told reporters in Damascus."Syria has the right ... to agree or not to agree on the nationalities of the observers," she added.An initial team of UN ceasefire monitors is due to arrive in Syria on Sunday evening and will be deployed on Monday, the spokesman for international mediator Kofi Annan said.They will be joined by at least two dozen more in coming days in line with a United Nations Security Council resolution adopted on Saturday authorizing their deployment, Ahmad Fawzi said.But Shabaan's comments will be seen by many as an attempt to control the international observers, whose mission is to oversee an already shaky 4-day-old truce. On Sunday, Syrian forces pounded the central city of Homs, activists said.Shabaan also hinted that Syria would not uphold the ceasefire if armed elements of the opposition attacked."It is Syria's right to respond to any acts of aggression against Syrian forces, civilians or private property," she said.According to Shaaban, the first group of 30 observers will sign a "protocol" with the Syrian government to pave the way for a further 220 monitors.Shaaban said the protocol had been agreed with General Robert Mood, a Norwegian who led a UN negotiating team in Syria earlier this month, and that further terms will be agreed with him when he returns to the country.Syria welcomes the monitors, she said, as they will see acts of kidnapping, killing and destruction carried out by "terrorists"."Spreading these monitors in Syria benefits the country," she said.The UN estimates Assad's forces have killed more than 9,000 people in the uprising. Syrian authorities say foreign-backed militants have killed more than 2,500 soldiers and police.