The Russian Foreign Ministry has warned against outside interference in the Syrian conflict, saying the country's citizens should solve their problems themselves.

"The settlement in this country should be carried out by the Syrians themselves without outside interference and should be based on an all-Syria dialogue, which is the only way to resolve the conflict," the ministry said in a statement.

Moscow's stance was voiced after French Foreign Minister Alain Juppe said earlier on Thursday that the UN Security Council may take a tougher stance on Syria if the ruling regime fails to halt its deadly crackdown on protesters.

Juppe's comments came as Syrian troops and tanks continued their assault on the city of Hama, a center of opposition protest, and just hours after the Security Council adopted a statement condemning the "widespread violations of human rights and the use of force against civilians by the Syrian authorities."

Speaking to reporters in Paris, Juppe hailed the international body's condemnation as a "turning point" but warned that the Council may "go further in its decisions" if nothing has changed in a week's time, when it will meet to "reexamine the situation."

UN Secretary General Ban Ki-moon said the Security Council statement represented "the clear message of the international community" to President Bashar al-Assad.

Residents and rights campaigners say at least 140 people have been killed in the unrest in Hama. More than 1,600 civilians are believed to have been killed since protests began in March.

Meanwhile, tens of thousands of people rallied in several Syrian cities late on Wednesday.