Russia on Tuesday urged Syria to be more active in implementing UN-Arab League envoy Kofi Annan's peace plan, while Syria said it had withdrawn troops from some provinces.

Speaking at the news conference after meeting with Syrian Foreign Minister Walid al-Moallem, Russian Foreign Minister Sergei Lavrov said the two sides had "a detailed discussion on the fulfillment of the Annan plan."

"The Syrian government has confirmed its intention to continue implementing all its obligations," Lavrov said.

The Russian top diplomat also called on the Syrian opposition and all countries that supported it to use all their influence to achieve a ceasefire in the crisis-torn country.

The United States and other countries that had direct and sustained channels of contact with the Syrian opposition should not shift the responsibility to Russia and China but use their means to stop the violence in the country, Lavrov said.

The minister said the Syrian government's requirement of written ceasefire guarantees from the opposition was not mentioned during his talks with Moallem.

Meanwhile, Lavrov said Moscow was ready to send representatives to the UN observer mission in Syria.

The observer mission would be a key factor to show the world "a more objective picture" of what was happening in Syria, he said, adding the mission would also make it possible to see which party was fulfilling the ceasefire obligations.

Moallem, for his part, said the Syrian government had pulled its troops out of some rural provinces and the ceasefire must start simultaneously with the deployment of the international observer mission.

The Syrian foreign minister said his country hoped the new observers would be impartial and fully register and report ceasefire violations by all parties.

Damascus would begin negotiations with the opposition after they accepted Annan's plan, he said, adding that Syria expected Annan to provide guarantees that the opposition would end fighting and not receive external support.

"We are prepared for such a dialogue from the moment Annan's six-point plan has been accepted by the Syrian opposition," Moallem told reporters.

The plan calls for the withdrawal of heavy weapons and troops from populated areas, a daily halt to fighting for the delivery of humanitarian aid and treatment of the wounded, and talks between the government and opposition.

Under the timeline accepted by the Syrian government and endorsed by the UN Security Council, military operations by government troops must stop by April 10. All violence should be halted 48 hours later.