BEIRUT -- Syrian government forces advanced deeper into the southern province of Daraa on Sunday under the cover of airstrikes, entering new villages amid reports that the U.S. has told rebels not to expect an American intervention to defend them from the army's offensive.

Syrian government forces have been on the offensive in eastern parts of Daraa province for the past five days in an operation that aims to reach a main border crossing point with Jordan. The push comes two months after government forces regained control of rebel-held eastern suburbs of the capital Damascus freed thousands of government soldiers for the new battle in Daraa province.

Opposition activists have been reporting for days that President Bashar Assad's government has sent some of its elite units to the south, including the Republican Guards and the Tiger force that is commanded by Brig. General Suheil al-Hassan. He is widely known as Nimr, Arabic for "tiger."

The Britain-based Syrian Observatory for Human Rights and Daraa-based opposition activist Osama Hourani said that the U.S. has informed rebel groups in southern Syria that Washington will not intervene in the operations to defend them against the government offensive that is ongoing under the cover of Russian airstrikes.

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Two U.S. officials discounted the claim. They spoke on condition of anonymity to discuss internal deliberations.

Denying the rebels support would be a reversal from earlier pronouncements. The U.S. warned last month that it would take "firm and appropriate measures" to protect a cease-fire in southern Syria if government forces move against rebels there. The region has also been a source of regional tensions between Iran and Israel in recent months.

"It is clear that since yesterday the Russians and the [Syrian] regime have been given the green light to regain control of Houran," Hourani said referring to the region that includes Daraa, the nearby region of Quneitra and parts of Sweida province. "The proof is that after the rebels received the [American] message Russian warplanes joined the battle."

The United States, Russia and Jordan agreed last year to include Daraa in a "de-escalation zone" and freeze the lines of conflict there. But the area has been tense after a series of recent Israeli strikes on Syrian and Iranian forces. Iran is a close ally of Assad, and its advisers are embedded with his troops.

The Syrian Arab News Agency said Sunday that troops made territorial gains in al-Lujat and other areas including the village of Jadal on the eastern edge of Daraa province.

Russia's Defense Ministry said some rebels have voluntarily joined forces with Syrian government forces adding that Syrian troops repelled an attack by al-Qaida-linked fighters in Daraa.

The Syrian state news agency said that rebels shelled the southern government-held city of Sweida wounding three people.

The Observatory said government forces reached the rebel-stronghold of Busra al-Harir where fighting is ongoing inside the town.

In an interview aired Sunday, Assad said Syria has not possessed chemical weapons since it got rid of them five years ago and that allegations of their use are a pretext for invasion by other countries. Assad's comments came in an interview with Russia's state-controlled NTV television channel.

"We fully eliminated chemical weapons. We haven't had them in Syria since 2013," Assad said in the interview.

Syria has been charged repeatedly with using chemical weapons in its civil war, most recently in April in the town of Douma. The United States, France and the United Kingdom launched air strikes in retaliation.

"Americans constantly lie and attack immediately," Assad said in the interview.

Assad said reconstructing Syria after the devastation wrought by the war could cost $400 billion, but said "we have enough means to restore our country, we are sure about that" and that funds could be sought from the Syrian diaspora.

Information for this article was contributed by Jim Heintz, Alice Su and Lolita C. Baldor of The Associated Press.

A Section on 06/25/2018