Major General Robert Mood of Norway arrived in the Syrian capital of Damascus Sunday afternoon to head a UN cease-fire observer mission, aimed at bringing an early end to the 13-month-old crisis in Syria.

Upon arrival at Damascus international airport, Mood expressed his "most sincere condolences to all Syrian families who have lost loved ones during violence."

"The mission is going to build on what the advance team has achieved," he said, adding "we will work for the full implementation of Kofi Annan's six-point plan as agreed by the Syrian Arab republic."

Mood said the team has now 30 observers and the number will double within the coming days, and will reach 300 later. However, observers' spokesman Neeraj Singh stressed to Xinhua that the number on ground is now still 15 not 30.

Meanwhile, Mood said the focus of his mission is "to engage all parties to achieve successful Kofi Annan's plan."

"We want to have a combined efforts focusing on the welfare of the Syrian people ... true cessation of violence in all its forms, " he said, adding that he will work with all parties to achieve this goal and achieve the "legitimate concerns and aspirations of the Syrian people."

Mood said the observers will come from many nations, but added that they alone "cannot solve all the problems ... so I call on all parties to help us and to cooperate with us in this very challenging task."

To make Annan's mission a success, "I call on all to stop the violence and to help us on a continued cessation of armed violence ... together we can make it ... we have that choice," he said.

On Friday, UN Secretary General Ban Ki-moon announced the appointment of Mood as the Chief Military Observer and Head of Mission of the UN Supervision Mission in Syria (UNSMIS), according to Ban's spokesperson Eduardo Del Buey.

UNSMIS is a mission consisting of up to 300 military observers, assigned by the UN Security Council with the task of monitoring a cease-fire between the Syrian government and the opposition forces.

The observers are also tasked with supporting a six-point plan for peace in Syria proposed by Annan, whose peace plan calls for the withdrawal of heavy weapons and troops from population centers, a daily halt in fighting for the delivery of humanitarian aid and treatment for the wounded, as well as talks between the government and the opposition.

The advance team of observers arrived in Syria 11 days ago to set the ground for the larger mission and to establish liaison with all concerned parties in the crisis. They also came to monitor the truce that practically went into effect on April 12.

However, since their arrival, the rate of violence has been notably amplified with reports of more assassinations, kidnappings and explosions, which had hit headlines almost every day.