United Nations and Arab League special envoy to Syria, Kofi Annan, warned Thursday that further militarisation in Syria will worsen a conflict there that has left thousands dead in a year.
The former UN chief said he feared any miscalculation on the issue risked destablising the region.
"I believe further militarisation will make the situation worse," Annan told reporters in Cairo after talks with Arab League Secretary General Nabil al-Arabi.
He warned of "the possible impact of Syria on the region if there is any miscalculation."
"I hope that no one is very seriously thinking of using force in this situation," he said, adding that diplomatic efforts should be kept up.
Nearly 8,500 people have been killed in the almost year-long crackdown on protests against President Bashar al-Assad's regime, the Syrian Observatory for Human Rights says, and world pressure has been growing for a new push to end the bloodshed.
"We have to be careful that we don't introduce a medicine that is worse than the disease," Annan said.
He called on "the Syrian opposition to come together to work with us to find a solution that will respect the aspirations of the Syrian people."
Annan has been holding talks in the Egyptian capital ahead of a trip to Damascus he said was now set for Saturday.
"We will do whatever we can to urge and press the cessation of hostilities and an end to the killing and violence," he said earlier, ahead of talks with Egyptian Foreign Minister Mohammed Amr.
"But of course the ultimate solution lies in the political settlement," he said.
For his part, Amr warned of consequences for the entire Middle East, should the crisis spiral, his spokesman said.
Amr said that an "explosion" of the situation "would not only have internal consequences but will spread to the whole region."
On Wednesday, Amr warned that arming rebel fighters in Syria, most of them army defectors, would "lead to an escalation in the military conflict and spark a civil war."
Some Arab countries, such as Qatar and regional powerhouse Saudi Arabia, have spoken in favour of arming the rebels.
The opposition Syrian National Council has said it wants to organise arms deliveries to the rebel Free Syrian Army and announced the formation of a "military bureau" to coordinate and serve as a conduit for weapons supplies from abroad.
Annan and his deputy former Palestinian foreign minister Nasser al-Qudwa, who will head to Damascus on Saturday, are acting under a UN General Assembly mandate as well as Arab League resolutions on the crisis.
A UN General Assembly resolution passed on February 16 demands that Syria "cease all violence and protect its population," free everyone detained in connection with the unrest, withdraw troops from urban areas and guarantee freedom of demonstration.
It also insists on "full and unhindered access and movement" for a currently suspended Arab League observer mission and international news media "to determine the truth about the situation on the ground."
Damascus has welcomed the visit by Annan and Qudwa.
"Syria welcomes the visit by Kofi Annan, the special envoy of the UN secretary general," state television said, citing an official it did not identify.