The U.K., France and Germany jointly condemned the escalating violence of the Assad regime and allied forces in the northwestern Syrian province of Idlib on Monday.

In a joint statement, the foreign ministries of the three European countries expressed growing concern over the well-being and safety of the civilian population residing in the last rebel-held province, calling on both sides to avoid military confrontation and to abide by their commitments to de-escalate violence in the province.

"France, Germany and the United Kingdom are gravely concerned by the current escalation of hostilities in north-western Syria," said the statement issued by the U.K.’s Foreign Office.

"Over recent days, the civilian population in the region has been under heavy shelling by the Syrian regime and Russia, with daily aerial raids and bombardments.

"This military escalation must stop," they urged.

Condemning the Syrian regime and the Russian allies for "indiscriminate bombardment," "use of barrel bombs," and "targeting of civilian and humanitarian infrastructures," they reiterated that such flagrant acts are violations of international humanitarian law.

The violence has resulted in the death of more than 120 civilians over the last weeks, according to the statement.

The statement also said that despite the presence of UN-designated terrorist groups in the Idlib province being of grave concern, the indiscriminate and brutal offensive on the besieged province is not about fighting terrorism, as the Syrian regime claims, rather it is about reconquering the territory.

In a four-nation Istanbul summit in September, Russia, Turkey, Germany and France expressed determination to reach a complete cease-fire in Idlib.

Separately, Turkey and Russia agreed in September to turn Idlib into a de-escalation zone in which acts of aggression would be expressly prohibited.

"This is paramount, to ensure the protection of civilians and safe and unhindered humanitarian access to alleviate their suffering," read the statement.

Last week, U.K. Foreign Minister Jeremy Hunt condemned military action by Russia and the Syrian regime, calling the offensive "a flagrant violation of the ceasefire agreement that Russia itself agreed with Turkey, is only compounding what was already a dire humanitarian situation in Idlib".

In recent weeks, the Syrian regime and its ally, Russia, have intensified attacks against the last major rebel enclave. The offensive threatens to unleash a major humanitarian catastrophe with 180,000 civilians already being forced to flee their homes in the last two weeks.

Some 1.5 million people reside in Idlib, half of whom are refugees from other parts of the country.