The United States said fighting and killing has continued in a war-battered suburb of Damascus as a humanitarian cease-fire Russia said it would enforce in eastern Ghouta came into effect.
"The Syrian regime, and its Russian and Iranian backers, continue to attack East Ghouta, a densely populated suburb of Damascus, despite the cease-fire called for by the United Nations Security Council" over the weekend, U.S. State Department spokeswoman Heather Nauert tweeted late on February 26.
"The regime claims it is fighting terrorists, but is instead terrorizing hundreds of thousands of civilians with air strikes, artillery, rockets, and a looming ground attack," she said.
"The regime's use of chlorine gas as a weapon only intensified the misery of the civilian population," Nauert said, in an apparent reference to allegations of a Syrian chemical attack on the suburb over the weekend.
"Russia has the influence to stop these operations if it chooses to live up to its obligations" under the UN cease-fire resolution, she said.
White House spokeswoman Sarah Sanders also called for an "immediate end" to offensive operations in Syria.
Russian Defense Minister Sergei Shoigu said on February 26 that President Vladimir Putin had ordered a "humanitarian pause" in Ghouta from 9 a.m. to 2 p.m. local time, starting on February 27.
Shoigu said a humanitarian corridor will be opened to allow civilians to leave the area under fire.
Yury Yevtushenko, a Russian official based in Syria, said that Syrian government troops would not carry out any air strikes during a five-hour pause Russia intends to enforce each day.
The United Nations and European countries called on Russia to expand the announced five-hour pause into a longer-lasting truce.
Britain’s Deputy UN Ambassador Jonathan Allen said Russia was playing "cynical games" and that the announcement shows that "Russia can implement if it chooses to. If it’s able to do a five-hour pause, it’s able to do a 24-hour pause."
"Five hours is better than no hours, but we would like to see any cessation of hostilities be extended," UN spokesman Stephane Dujarric said.
The UN resolution demanding a 30-day cease-fire was passed on February 24 after reports from activists that the siege on eastern Ghouta had killed more than 550 people in a matter of days.
"We need to see the cease-fire put in place," said EU foreign policy chief Federica Mogherini. "Every single minute we wait, there are people dying."
A UN spokeswoman said that at least 30 civilians had been killed in eastern Ghouta -- where some 400,000 people live -- in the days since the cease-fire resolution was passed.
The Britain-based Syrian Observatory for Human Rights said air strikes and shelling killed at least nine civilians on February 26, a day after a suspected chlorine gas attack in the rebel-held territory.
Russia and Iran have given Assad's government crucial support throughout the seven-year war in Syria, which began with a government crackdown on peaceful protests.
Moscow helped turn the tide of the conflict in Assad's favor by launching a campaign of air strikes in 2015 and stepping up its military presence on the ground.
Meanwhile, Russian Foreign Minister Sergei Lavrov said on February 26 before Shoigu's announcement that the truce does not apply to “terrorist groups.”
"We will never support any actions aimed at exempting terrorists from a legitimate strike," he said.
The UN resolution affirmed that the proposed cessation of hostilities would not apply to military operations against the jihadist groups Islamic State (IS), Al-Qaeda, and the Al-Nusra Front. Many Al-Nusra Front fighters reside in eastern Ghouta.
Syria and its allies Russia and Iran often refer to Sunni rebels as "terrorists," including groups allied with Western countries and Arab states as well as extremist groups like the Al-Nusra Front.
Lavrov also said that reports of an alleged chemical attack in eastern Ghouta were "fake stories," despite videos and photos of alleged victims of the attack shown in the media.
The Syrian government denies using chemical weapons, although a UN investigation has documented the use of such weapons on multiple occasions.