Syria's foreign minister has said US-led air strikes had failed to weaken the grip of the Islamic State of Iraq and the Levant (ISIL) in Syria and the group would not be tackled unless Turkey was forced to tighten border controls.
A US-led alliance started attacking ISIL targets in Syria in September as part of a wider effort to destroy the al-Qaeda offshoot that has seized large areas of the country and neighbouring Iraq.
"All the indications say that (Islamic State) today, after two months of coalition air strikes, is not weaker," Walid al-Moualem, the foreign minister, said in an interview with the Beirut-based Al Mayadeen TV broadcast on Friday.
The Syrian government has said it was willing to join the fight against ISIL, but the US refuses to deal with President Bashar al-Assad, who it says has lost legitimacy and must leave power.
"If the Security Council and Washington do not force Turkey to control its borders then all of this action will not eliminate [ISIL]," Moualem said, referring to foreign fighters who have crossed into Syria from Turkey.
Turkey, which has a 900km frontier with Syria, has strongly denied accusations it has supported fighters, inadvertently or otherwise, in its enthusiasm to help Syrian rebels topple Assad.
Turkish designs alleged
Thousands of foreign fighters are believed to have joined the ISIL in their self-proclaimed caliphate, carved out of eastern Syria and western Iraq.
Moualem said Turkish calls for the establishment of a no-fly zone in northern Syria would lead to the partition of the country, adding that Turkey had designs on Syrian territory.
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Turkey has repeatedly said a no-fly zone should be put in place to create safe areas in Syria, allowing Syrian refugees in Turkey to be repatriated.
Turkey's idea has received a cool reception from its allies. A NATO general said this week the idea was not being considered.
Moualem held talks with Russian President Vladimir Putin and Sergey Lavrov, Russian foreign minister, on the Black Sea as part of a renewed Russian diplomatic push to restart peace talks on Syria.
The effort is unlikely to get far because Russia rejects calls by Assad's Syrian, Western and Arab opponents for his swift departure.
"After our discussions with the Russian side we agreed that the dialogue will be with the national opposition that is not linked to the outside," Moualem said.
The Syrian civil war, which began three and a half years ago as an uprising against Assad's regime has killed an estimated 200,000 people, with the UN and rights groups repeatedly urging Syria to refrain from targeting civilian areas.