DAMASCUS, Syria (AP) -- Syrian government forces were on the verge Thursday of recapturing Palmyra, an ancient town in central Syria controlled by the Islamic State group, having pushed closer to its outer edges with the support of Russian airstrikes.
The government forces were now within 1 kilometer (half mile) from the heart of the town, a Syrian official and an opposition monitoring group said.
Recapturing the town, a UNESCO world heritage site, would be a significant victory for the army and its Russian allies. Russia withdrew most of its forces and aircraft from Syria last week after a months-long bombing campaign that succeeded in turning the tide of the war again in President Bashar Assad's favor.
From the nearby city of Homs, Gov. Talal Barazi told The Associated Press that the Syrian army has determined three directions to storm Palmyra and was now clearing all roads leading into the town of mines and explosives.
"We might witness in the next 48 hours an overwhelming victory in Palmyra," he said over the phone, adding that "the army is advancing in a precise and organized way to protect what is possible of monuments and archaeological sites."
The Britain-based Syrian Observatory for Human Rights said hat Syrian troops and Shiite militiamen helping them on the ground were facing tough resistance from IS extremists as they try to penetrate the town's limits.
The group, which monitors the Syrian conflict through a network of activists on the ground, said the IS lost over 200 militants since the government campaign to retake Palmyra began 17 days ago. The Observatory did not have figures for government losses.
Palmyra attracted tens of thousands of tourists to Syria every year and is affectionately known by Syrians as the "bride of the desert." In a big blow to the government, it was overrun by the Islamic State group last May.
In Palmyra, the IS destroyed many of the town's Roman-era relics, including the 2,000-year-old Temple of Bel and the iconic Arch of Triumph, and also killed dozens of captive Syrian soldiers and dissidents from IS in public slayings at the town's grand roman theater and other ruins.
Along with blowing up priceless archaeological treasures, among the first destructions IS carried out in Palmyra was the demolishing of the town's infamous Tadmur prison, where thousands of Syrian government opponents had been imprisoned and tortured over the years.
The advance on Palmyra comes against the backdrop of Syrian peace talks underway in Geneva between representative of the Damascus government and the Western-backed opposition. The talks, which have been boosted by a Russia-U.S.-brokered cease-fire that has mostly held since late February, were to adjourn on Thursday -- without having achieved any apparent breakthroughs.
The negotiations are scheduled to resume later in April.
In Moscow, U.S. Secretary of State John Kerry called on Thursday for countries to boost efforts to fight IS in Syria, Iraq and beyond in the wake of this week's deadly attacks in Brussels. He said the Brussels attack should put nations on notice that the terror threat emanating from the Middle East must be stopped.
Kerry is in Moscow for talks with Russian President Vladimir Putin and Foreign Minister Sergey Lavrov on Syria, Ukraine and the Brussels attacks. He will be seeking clarity from Putin and Lavrov as to where Russia stands on a political transition for Syria, particularly on the issue of Assad's future.
Despite its recent drawdown in Syria, Moscow has said it is keeping its bases in Syria and would continue to carry out airstrikes against the Islamic State group and other extremists. The Russian air force has supported the Assad government advance with a fierce campaign of air strikes.
Meanwhile, the U.N. chief arrived in Lebanon on Thursday for a two days visit during which he is expected to meet top Lebanese officials and discuss regional matters. Lebanon, which has taken in over 1 million Syrian refugees, is also host to a U.N. peacekeeping force that maintains security along the Lebanese-Israel border.
Ban is expected to address refugee support, youth unemployment, and private sector development. He will visit a Syrian refugee settlement in central Lebanon and the country's second-largest city, Tripoli, in the north.
The secretary general will be joined by World Bank and the Islamic Development Bank Group representatives on a five-day regional tour that will also take him to Jordan and Tunisia.