(CBS/AP) TEHRAN, Iran - Special envoy Kofi Annan said Wednesday in Tehran that Iran could help solve the crisis in Syria, where activists reported fresh violence near the capital Damascus a day before an international cease-fire is supposed to take effect.
Iran is one of Syria's strongest allies, and former U.N. chief Annan went there to bolster support for his faltering plan to stop the country's slide toward civil war.
"Iran, given its special relations with Syria, can be part of the solution," Annan said during a news conference with Iran's Foreign Minister Ali Akbar Salehi. "The geopolitical location of Syria is such that any miscalculation and error can have unimaginable consequences."
The conflict in Syria is among the most explosive of the Arab Spring, in part because of the country's allegiances to powerful forces including Lebanon's Hezbollah and Shiite powerhouse Iran. The uprising that began more than a year ago seeks the ouster of authoritarian President Bashar Assad.
Iran has opposed any foreign intervention in the crisis and Salehi insisted that "change in Syria" should come under the leadership of Assad.
Syria's regime defied the Tuesday deadline to pull out troops from cities and towns that was set in the deal brokered by Annan and launched fresh attacks on rebellious areas.
But Annan insists there is still time to salvage the truce by 6 a.m. Thursday, the deadline for government and rebel fighters to cease all hostilities.
"We've been in touch with them (Syrian rebels) and have had positive answers from them. ... I think by 6 in the morning on the 12th, Thursday, we should see a much improved situation on the ground," Annan said.
"It is possible to do it and it should be in the interests of the people of Syria," he added.
Annan's appeal to Iran comes a day after U.S. Sen. John McCain, R-Ariz., told CBS News correspondent Clarissa Ward in Turkey that he has no doubt whether the peace plan was a failure.
McCain and Connecticut independent Sen. Joe Lieberman -- both strong advocates of international intervention -- visited a Syrian refugee camp inside Turkey Tuesday, which was supposed to be the first day of a cease-fire under Annan's peace plan.
Turkey's Deputy Prime Minister Besir Atalay, who met Annan on Tuesday, said the international envoy "appeared worried to me." Atalay told Turkey's TV 24 channel that the Syrian regime is not fulfilling its promise and while withdrawing its forces from one area, it is deploying them in another.
He added that if Annan's plan does not succeed in ending the violence in Syria, "the world will rethink. This time, the U.N. Security Council will have no excuses. It will be more difficult to use their veto right." He was referring to Russian and Chinese vetoes of two past Security Council resolutions condemning Assad's regime for the crackdown on protesters.
There was more violence on Wednesday, putting the chances of a truce even deeper in doubt. Syrian troops took control of large parts of villages and towns near the border with Turkey.
Syrian state-run news agency SANA said gunmen shot and killed army Brig. Gen. Jamal Khaled in the Damascus suburb of Aqraba on Wednesday morning. It added that Khaled's driver, a soldier, was also killed in the attack.
The Britain-based Syrian Observatory for Human Rights activist group reported clashes in the Barada Valley region on the outskirts of Damascus between troops and army defectors as government forces stormed the area. The Observatory said dozens of people were wounded.
Activist Fares Mohammed said two people were killed and dozens wounded when government troops stormed and shelled Barada valley as well as damaging tens of homes.
"Many of the wounded lost limbs as a result of shelling by tanks," he said.
The Local Coordination Committees, an activist network, reported shelling of several rebel-held neighborhoods in the central city of Homs.
The Observatory said "tens of army vehicles" are deploying in the southern town of Maaraba. The Observatory added that two people were killed in the eastern town of Qoriah during raids by regime force.
Activist Mohammed Abu Nasr said Syrian forces entered the border town of Azaz, about two miles from the Turkish border and set homes of activists on fire.
In a letter to the U.N. Security Council, obtained by The Associated Press, Annan said Tuesday that Syria has not pulled troops and heavy military equipment out of cities and towns, and that the regime's last-minute conditions put the entire cease-fire at risk.
The council strongly backed Annan, with all 15 members including Syrian allies China and Russia approving a media statement expressing "deep concern" at the failure by Damascus to withdraw its troops and heavy equipment.