UNITED NATIONS (AP) — The U.N.'s top envoy for Syria announced Wednesday that new talks between Syria's government and opposition will take place "in about a month" and said this eighth round must finally move to "genuine negotiations on the political future" of the war-ravaged country.

Staffan de Mistura told the U.N. Security Council that both sides should use the coming month to create conditions for the talks in Geneva "to be meaningful," and to participate "without preconditions."

His announcement that talks will start no later than the end of October or very early in November comes as the Syrian government reverses military losses in much of the country's strategically important west and as foreign governments cut support for rebel forces.

With the civil war now more than 6 1/2 years old, Syrian President Bashar Assad and his allies have taken control of the country's four largest cities and its Mediterranean coast. Backed by Russian air power and Iranian-sponsored militias, pro-government forces have marched across energy-rich Homs province and were fighting Wednesday on the east bank of the Euphrates River.

De Mistura told the council that fighters for the Islamic State extremist group are "being beaten back." He pointed to the breaking of a three-year siege of Deir el-Zour city by IS, also known as ISIS, and the U.S.-led international coalition taking control of most of the city of Raqqa, once the de facto capital of the militant group's self-styled caliphate.

He pointed to the creation of four de-escalation zones as "an important next step" in efforts to reduce violence.

These zones should be a precursor "to a truly nationwide cease-fire" and action to provide humanitarian aid to all in need, he said. Talks in Kazakhstan's capital of Astana, which have focused on local cease-fires and de-escalation zones, "should be seen as laying the basis for a renewed Geneva process," he added.

De Mistura called on both Syria's government and opposition to use the weeks before the next talks "to assess the situation with realism and responsibility."

He said the divided opposition has "a duty to signal that it wants to speak with one voice and a common platform in genuine negotiations with the government." The government has a duty "to genuinely negotiate with the opposition," he said.

De Mistura said both sides should show readiness to negotiate on four key issues: "credible" and "inclusive" local and central governance; a schedule and process for drafting a new constitution; U.N. supervised elections; and combating terrorism.

On the humanitarian front, U.N. humanitarian chief Mark Lowcock told the council that during July and August the U.N. and its partners reached only 280,500 of the 1.23 million people it sought to assist. He blamed "bureaucratic delays and blockages by all sides."

U.S. Ambassador Nikki Haley accused the Syrian government of denying aid to besieged and suffering communities and she said it has refused to come to the negotiating table "in good faith."

"If the Syrian people don't see a political process working in parallel with our de-escalation efforts, the violence will resume," she warned. "The only lasting solution in Syria — the only way to end the violence and defeat terrorism — is through a political transition, one that does not allow Iranian influence to replace ISIS or Assad in power."