U.S. Secretary of State Hillary Clinton has called on Russia to stop selling weapons to Syria, where a crackdown on pro-democracy demonstrators by the regime of President Bashar al-Assad has claimed some 2,000 lives.

"We want to see Russia cease selling arms to the Assad regime," Clinton said in an interview with CBS news on Thursday.

Russia joined in early August the growing international condemnation of the violence in Syria after security forces intensified their crackdown on protesters with the beginning of the holy Islamic month of Ramadan. President Dmitry Medvedev said Russia may make "some kind of decisions" against the Syrian government if al-Assad does not restore peace in the country and conduct reforms.

World powers, including Arab states, voiced their concern about the situation in Syria earlier this month after more than 300 people were killed by pro-government troops, mainly in the cities of Hama and Deir al-Zor, in just a week.

When asked if the United States intended to urge Assad to step down, Clinton said: "Well, I think we've been very clear in what we have said about his loss of legitimacy... We are, I think, building the chorus of international condemnation. And, rather than, you know, us saying it and nobody else following, we think it's important to lead and have others follow as well."

U.S. media have reported that Washington is planning to call on Assad to step down in the next few days, rather then just condemn his crackdown on protesters.

"What we really need to do to put the pressure on Assad is to sanction the oil and gas industry," Clinton said, adding that Europe, as well as China and India - who have made large investments in Syria's energy sphere - should support the sanctions.

At a meeting with a delegation of diplomats from Brazil, India and South Africa on Wednesday, Assad admitted that his security forces had made "some mistakes" in quelling nationwide protests over the last five months. He also promised to go along with reforms and continue dialogue with the opposition.