U.N. Secretary-General Ban Ki-moon says violence against Syrians has continued despite his repeated calls for President Bashar al-Assad to halt “excessive and lethal” actions by government security forces.

Speaking Thursday at the University of Sydney in Australia, Mr. Ban said he has urged Mr. Assad to carry out political reforms “before it is too late.”

Rights activists said the crackdown continued Thursday with heavy gunfire as military vehicles stormed a village in northwestern Syria. The operation comes a day after activists said security forces killed at least 20 people during raids against anti-government protesters, mostly in the central Homs region.

France on Wednesday accused Syria of committing “crimes against humanity” in the crackdown.

French Foreign Minister Alain Juppe condemned the violence, saying international sanctions against Syria are justified. He met with Russian Foreign Minister Sergei Lavrov and urged Russia to take a stronger stance against Syria. Lavrov said his country still favors using dialogue to resolve the unrest.

The U.S. Ambassador to the United Nations, Susan Rice, said Wednesday it is “past time” for a Security Council resolution to pressure Syrian President Bashar al-Assad's government. She said support for additional measure is not yet unanimous, but members will continue working towards a “meaningful resolution.”

Also Wednesday, Iranian President Mahmoud Ahmadinejad said Mr. Assad, should back away from his violent crackdown on protesters and enter talks with the opposition.

During a live interview in Tehran with a Portuguese television station , the Iranian leader said “a military solution is never the right” one. He said problems must be dealt with through dialogue.

Earlier this year, Iranian security officials used tear gas and electric batons to disperse anti-government protesters in Tehran. Scores were arrested. And at least 72 people were killed during the crackdown on protests after Iran's disputed 2009 presidential elections. Iranian authorities also arrested hundreds of people and sentenced more than 80 of them to prison.

Meanwhile, President Assad's government delayed a planned Arab League visit expected to begin Wednesday. The league said Secretary-General Nabil Elaraby now plans to visit Syria on Saturday.

Elaraby has said he wants to express Arab concerns about the violence in Syria and listen to the opinions of Syrian leaders. Last month, Syrian authorities rejected an Arab League statement calling for an end to the bloodshed.

The United Nations estimates 2,200 people have been killed since March after Mr. Assad launched the crackdown on dissent. However, Syria has blamed much of the violence on armed gangs and “terrorists.”