Assad defies US

Syrian government helicopters dropped barrel bombs on opposition areas of the country's southwest yesterday for the first time in a year, a war monitor and rebel officials said, in defiance of US demands that President Bashar al-Assad halt the assault.

Assad has sworn to recapture the area bordering Jordan and the Israeli-occupied Golan Heights and the army this week began ramping up an assault there, threatening a "de-escalation" zone agreed upon by the United States and Russia last year.

The United States on Thursday reiterated its demand that the zone be respected, warning Assad and his Russian allies of "serious repercussions" of violations. It accused Damascus of initiating air strikes, artillery and rocket attacks.

United Nations Secretary-General Antonio Guterres on Friday demanded an immediate end to military escalation in southwestern Syria, saying he was "concerned at the significant risks these offensives pose to regional security," a spokesman for the UN chief said.

U.S. Ambassador to the United Nations Nikki Haley said earlier on Friday that the Syrian military escalation "unambiguously violates" the de-escalation arrangement and that over 11,000 people had already been displaced.

"Russia will ultimately bear responsibility for any further escalations in ‎Syria," Haley said in a statement.

A major offensive would risk a wider escalation that could draw the United States deeper into the war. The southwest is of strategic concern to US-allied Israel, which has this year stepped up attacks on Iran-backed militia allied to Assad.