More than half of Idlib is controlled by militants from Syria's former Al-Qaeda affiliate, Hayat Tahrir al-Sham (HTS), while much of the rest is held by rebels backed by Turkey.
The UN's Syria peace envoy, Staffan de Mistura, called on Russian strongman Vladimir Putin and his Turkish counterpart, Recep Tayyip Erdogan, to urgently speak on the phone even before they are set to meet with their Iranian counterpart in Tehran on Friday.
The US says it will respond "swiftly and appropriately" if Syrian President Bashar Assad uses chemical weapons "again", suggesting that Damascus was behind an April "attack" which Moscow says was entirely staged.
His comments came as Syrian troops gathered near the north-western region of Idlib for a major assault that has raised fears of a humanitarian catastrophe on a scale not yet seen in the seven-year-old conflict.
Germany would consider boosting humanitarian assistance for Syrian refugees in countries neighbouring state in the case of an all-out regime offensive in the northern region of Idlib, said Maas.
"President Donald J. Trump has warned that such an attack would be a reckless escalation of an already tragic conflict and would risk the lives of hundreds of thousands of people", she added.
Russian Federation has been a key supporter of Assad and complained about militants in Idlib targeting its own facilities.
Air raids across the province killed at least 13 civilians, including six children, the Syrian Observatory for Human Rights war monitor said.
On Wednesday, regime artillery and rocket fire targeted several areas in the province including the HTS-held town of Jisr al-Shughur, according to the Britain-based Observatory, which relies on a network of sources inside Syria.
Moscow has been carrying out strikes in Syria since September 2015, using aircraft at the Hmeimim base in Latakia province.
Cavusoglu said a common strategy was required to eliminate terrorist groups in Idlib but the continuation of attacks could be disastrous.