Iran's state TV reported on Tuesday that international envoy on Syria Kofi Annan has arrived in Tehran, amid continued attampts to find a peaceful resolion to the Syrian crisis.

The Tuesday report says the joint UN and Arab League envoy and his six aides will meet Iranian leaders to discuss ongoing violence in Syria.

Iran is Syria's main ally in the region. Annan has been pushing Damascus to withdraw its troops from cities and halt all violence in 48 hours to salvage his peace plan.

Speaking earlier Tuesday, Annan said there should be no preconditions to halting violence in Syria and insisted a UN-sponsored peace plan designed to stem 13-months of conflict was still on the table.

Just hours before the end-of-day deadline for Syria to implement the ceasefire plan, Annan said Syrian forces had withdrawn from some areas but moved to others not previously targeted, and the situation was not as he had hoped.

"I believe it's a bit too early to say that the plan has failed, the plan is still on the table," he told a news conference at the airport in Hatay province in southern Turkey.

"It's a plan we're all fighting to implement,... it's a plan the Syrians have endorsed and from the comments made by the opposition, they're also prepared to go along with it if the government meets its commitments to pull the troops out."

Earlier on Tuesday Syria's foreign minister, speaking in Moscow, said Damascus wanted guarantees from Annan that armed groups attacking its troops would commit to a ceasefire.

And in the meantime on Tuesday, Syrian troops killed 31 people and continued to shell the city of Homs.

"I believe there should be no preconditions for stopping violence. That is something we need to do for the people and for the country concerned," Annan said.

"I had hoped that by now we would have been much further ahead along the road to the government of Syria honoring its commitments and all the parties beginning to take steps to end all violence."

"We still have time between now and the 12th to stop the violence," he added.