Syrian President Bashar al-Assad’s ferocious pre-Ramadan assaults on his own people are shocking some Islamic countries and raising pressure on a reluctant United Nations Security Council to take action against the Assad regime.

President Obama on Monday issued a statement saying he is “appalled by the Syrian government’s use of violence and brutality” and promising to increase international pressure on Mr. Assad “in the days ahead.”

The statement followed reports that Syrian troops killed as many as 140 people Sunday in assaults on demonstrations in several cities that have been hotbeds of the opposition movement. That brings the total killed in four months of violence to over 1,600, according to human rights organizations.

The US will “work with others around the world to isolate the Assad government and stand with the Syrian people,” Mr. Obama said.

That is likely to mean a renewed effort to at least issue a condemnatory statement in the UN Security Council, where European countries were already pressing Monday to move Syria back onto the agenda. The council was expected to hold an emergency session on Syria later Monday.

US and European efforts to see the Security Council approve any resolution against Syria, even one devoid of sanctions, have faced opposition from a range of rising global powers – from Russia and China to India, Brazil, and Turkey. Those countries are unhappy with the way Western powers and NATO interpreted a Security Council resolution on Libya in late February as an open door to military intervention against Libyan leader Muammar Qaddafi.

Colonel Qaddafi, like President Assad now, was ordering the military to attack civilians involved in anti-regime uprisings.

With Russia and China – both veto-wielding permanent members of the Security Council – threatening to stop any resolution, Western efforts stalled. But Sunday’s violence, coming as it did on the eve of the holy month of Ramadan, may have tilted the balance in favor of action, some Security Council analysts believe.

Most notable was a shift in tone from Turkey, which overnight Sunday went from merely disapproving of Assad’s actions to declaring them “unacceptable.”

“Beginning the holy month of Ramadan with bloodshed is unacceptable,” said Turkish President Abdullah Gul, according to the state news agency Anadolu Ajansi. He added that it had become “not possible for us to remain indifferent to this violence,” although he did not specify what kind of action Turkey might consider.

Turkey is a member of NATO but it also has a close relationship and strong economic ties with Syria, and has rejected sanctions in the past.

The European Union (EU) on Monday added five members of the Syrian regime to its list of now 35 Syrian officials targeted by specific economic and diplomatic sanctions.

The US in May announced sanctions against President Assad and six other top officials in the regime. The US could follow the EU and add to the list of officials under American sanctions, but the Obama administration is expected to join its EU partners in pressing for passage of the dormant Security Council resolution on Syria.