<div>United States has warned action on Syria if UN Security Council failed in its duty.&nbsp;</div>''<div><br />''</div>''<div>Nikki Haley, US Ambassador to United Nations told 15-member Security Council at the UN on Monday that when international community consistently failed to act, there were times when states were compelled to take their own action.</div>''<div><br />''</div>''<div>Meanwhile, in Syria, regime forces' jets carried out first aerial attacks in rebel-held towns in southern parts of country since United States and Russia reached an agreement making it a de-escalation zone last year.&nbsp;</div>''<div><br />''</div>''<div>At least eight raids struck rebel-held towns of Busr al-Harir, Hrak, al-Gharaiya al-Gharbiya and al-Sowara in rural areas in eastern Deraa province in southern Syria.</div>