As the conflict in Syria entered its 10th year Sunday, France, Germany, the U.K. and the U.S. called on the Syrian regime to end its killings and engage in a political settlement on the basis of a U.N. resolution.

In a joint statement, the four world powers said the Bashar Assad regime must accept the aspirations of its citizens, who demand to live in peace.

The countries demanded the regime "stop the ruthless killing and engage meaningfully in all aspects of UNSCR 2254, including a nationwide cease-fire, a reformed constitution, the release of arbitrarily detained persons, as well as free and fair elections."

They were referring to the Security Council's measure that endorsed a road map for a peace process in the war-torn country.

The statement said Syrian citizens, including those who are displaced and refugees, should be allowed to participate in free and fair elections under U.N. supervision.

The four countries also slammed the "reckless military offensive" by Assad, Russia and Iran in Idlib province in northwest Syria, which they said caused further suffering and an unprecedented humanitarian crisis.

Medical and humanitarian infrastructure and workers, as well as civilians, have been killed during the offensive that started in December, according to multiple reports.

"A nationwide cease-fire must be established," they said.

Idlib falls within a de-escalation zone laid out in a deal between Turkey and Russia in late 2018. The Syrian regime and its allies, however, have consistently broken the terms of the cease-fire, launching frequent attacks inside the zone.

"We will continue to demand accountability for the atrocities committed by the Assad regime and we will continue our efforts to make sure that those who are responsible for crimes against humanity, war crimes, and other violations and abuses are identified and held accountable," the statement said.

The four countries also urged the international community to continue to provide assistance to Syria's neighbors to share the costs of Syria's refugee crisis.

Syria has been locked in a vicious civil war since early 2011 when the regime cracked down on prodemocratic protests.

Since then, hundreds of thousands of people have been killed and more than 10 million others displaced, according to U.N. officials.