The Latest: Iran's army chief of staff visits Aleppo

BEIRUT (AP) - The Latest on developments in Syria (all times local):

1:50 p.m.

Iran's army chief of staff and other senior officers from the Iranian military have visited a front line in the northern province of Aleppo saying that the extremists' presence in Syria is coming to an end.

Iran has been one of Syrian President Bashar Assad's strongest supporters since the country's crisis began more than six years ago and has sent thousands of Iranian-backed militiamen to boost his troops against opponents.

Syrian government forces and Iran-backed groups have scored major victories against the Islamic State group in eastern Syrian recently capturing last week the IS stronghold of Mayadeen. Syrian troops and allied fighters are now marching toward the town of Boukamal on the border with Iraq.

The government-controlled Syrian Central Military Media on Friday quoted Maj. Gen. Mohammad Bagheri as expressing happiness "to witnesses the success of the axis of resistance." He was referring to a coalition of Iran, Syria, Iraq and Iran-backed groups in the region.

SCMM released two photographs showing Bagheri and other officers in a desert area.

On Thursday, Syrian state media said Assad met Bagheri during which they discussed military cooperation.

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12:40 p.m.

A U.S.-backed Syrian force has declared victory over the Islamic State group in its former "capital" of Raqqa, declaring the city free of any extremist presence.

At a press conference held inside the city Friday, the Kurdish-led force known as the Syrian Democratic Forces formally handed over administration of the city in northern Syria to a council made up of local officials and tribal leaders.

"Our victory is one against terrorism," said Talal Sillo, a spokesman and senior SDF commander.

The press conference was held inside the city's sports stadium which Islamic State militants had turned into a huge prison where they incarcerated and tortured their opponents.

Sillo urged the international community and aid organizations to assist with the city's reconstruction

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11:15 a.m.

Russia's military says a recent travel warning by the U.S. State Department proves Moscow's argument that Syrian militants - and not the Syrian government - have used chemical weapons.

The U.S. State Department issued a travel warning on Wednesday, saying that the tactics of the extremists in Syria include the use of chemical weapons among other things.

The Russian Defense Ministry said in a statement on Friday that the travel warning proves Moscow's point that the extremists, not the Syrian government, are to blame for a deadly chemical weapons attack in a town in Syria's east.

The Organization for the Prohibition of Chemical Weapons earlier this month said it had found traces of sarin following an attack in northern Syria in March, days before a deadly strike using the same nerve agent in Khan Sheikhoun. The government has denied responsibility for that attack.

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10:50 a.m.

A U.S.-backed Syrian force is expected to declare victory in the northern city of Raqqa days after it said it cleared it from members of the Islamic State group.

The Kurdish-led Syrian Democratic Forces is scheduled to hold a news conference at noon Friday during which the city will be declared free of extremists.

The SDF is also expected to hand over authority in the city to a local council and a 3,000-member police force made up mostly of residents of Raqqa province.

The fall of Raqqa marks a major defeat for IS, which has seen its territories steadily shrink since last year. IS took over Raqqa, located on the Euphrates River, in January 2014, and transformed it into the epicenter of its brutal rule.