Militants in Syria's Idlib province failed to meet an October 15 deadline for vacating a buffer zone created under a Russian-Turkish cease-fire deal, prompting a threat from the Syrian government to resume its military campaign.
Syrian Foreign Minister Walid al-Moualem said Syrian forces are ready to resume their fight to "eradicate" militants who remain in Idlib, but he said Syria would give Russia time to determine whether they complied with the deal.
The deal between Turkey and Russia, which averted what was widely expected to be a bloody battle in the last remaining Syrian rebel-held stronghold last month, set up a buffer zone about 20 kilometers long which was to be evacuated of all heavy weapons and Islamist extremists by midnight on October 14.
Rami Abdel Rahman, the head of the Syrian Observatory for Human Rights war monitor, said on October 15 that the militants largely failed to comply with the agreement.
"We did not document the withdrawal of any jihadist fighters from the entire demilitarized zone," he said.
Moualem said at a press conference in Damascus that it is now up to Russia to judge whether the agreement has been fulfilled, and that may take time.
"We have to wait for the Russian reaction. Russia is monitoring and following the situation," he said.
"Our armed forces are ready around Idlib to eradicate terrorism if the Idlib agreement is not implemented," he said
"Idlib, as any other province, has to return to Syrian sovereignty. We prefer to have it through peaceful means, through reconciliation, but if not, there [are] other options."
Russian officials have hinted they could accept a brief delay in carrying out the agreement if it meant the spirit of the deal was still upheld.
Tahrir al-Sham, an Islamist alliance led by Al-Qaeda's former Syrian affiliate, on October 14 issued a statement lauding the cease-fire deal but pledging to continue its fight against the government.
"We value the efforts of all those striving - at home and abroad - to protect the liberated area and prevent its invasion and the perpetration of massacres in it," but "we have not abandoned our choice of jihad and fighting towards implementing our blessed revolution," the group said.
Tahrir al-Sham and other, more extreme Islamist groups hold over two-thirds of the buffer area, and over half of the rest of Idlib.
Idlib's other main rebel faction, a Turkish-aligned alliance of groups known as the National Liberation Front, has repeatedly expressed its support for the agreement.
Moualem said the government's next target after recovering Idlib from rebels would be the area east of the Euphrates -- territory which is currently held by the Kurdish-led Syrian Democratic Forces which are allies of the United States.
Kurdish leaders reportedly have traveled to Damascus to negotiate with the government over the future of the area they liberated last year from the Islamic State extremist group and where they have started to institute a system of self-rule with encouragement and protection from U.S. forces.
But Moualem suggested those negotiations have not produced any accord, and said the Kurdish-held area remains fair game for Syrian President Bashar al-Assad's forces -- even if that means clashing with U.S. troops in the area.
His statement came as Syria reopened two key border crossings with Israel and Jordan on October 15 that had been closed for years during Syria's seven-year civil war, which has killed over 400,000 people and displaced millions more.
The opening of the Nassib and Quneitra crossings are a major boost for Assad, showing that he is slowly reasserting control over much of Syria's territory.
The Nassib crossing with Jordan is a gateway to the oil-rich Gulf nations and important commercial artery that had been closed since 2015, when rebels seized control of it.
The Syrian army recaptured it in July, as it made gains across the country with the help of Russian and Iranian forces.