Dueling U.N. resolutions calling for a cease-fire in the Idlib region of Syria were both defeated Thursday, leaving millions at risk amid a brutal government offensive, aided by Russian airstrikes, and a looming humanitarian disaster.

Failed Security Council resolutions to stop the fighting have marked the Syrian war virtually since it began eight years ago, and these were no different.

Russia and China vetoed the measure supported by the majority of members of the 15-member council. The other permanent members — the United States, Britain and France — vetoed the plan proposed by Russia, which a senior U.S. official said was a “license to kill in Idlib and anyplace else.”

Idlib remains the last major holdout of opponents of the government of Syrian President Bashar al-Assad, who have long been included in his expansive definition of terrorism. Millions of civilians in the region of northwest Syria, many displaced by the long war, have borne the brunt of a five-month government offensive in which Russian airstrikes have targeted towns and villages far from the front lines.

The non-Russian draft resolution, sponsored by Belgium, Germany and Kuwait, garnered 12 votes. It called for “the immediate halting of any indiscriminate aerial bombardments resulting in civilian casualties” and said “counterterrorism operations do not absolve parties to armed conflicts of their obligations under international humanitarian law.”

“The Russians know we’re talking about them,” said the U.S. official, who spoke on the condition of anonymity under administration rules. “That is a new development.”

The carnage in the northwest continues as the United States and Turkey have begun joint air and ground patrols in northeast Syria, as part of an attempt to establish a “safe zone” in an area cleared of Islamic State fighters.

Turkey had demanded the zone also be cleared of the primary ground force allied with the Americans in the effort, the Syrian Kurdish fighters known as the People’s Protection Units, or YPG. Turkey considers the fighters terrorists, allied with Kurdish militants fighting for autonomy in Turkey.

Turkish President Recep Tayyip Erdogan has threatened to invade the region to establish a corridor under the control of his military forces if the United States does not push the Kurdish fighters back into Syria from the Turkish border. He has said he plans to move up to 3 million Syrian refugees in Turkey into the corridor.

The United States proposed a narrower safe zone, just a few miles wide, and has established a center to arrange joint supervision with Turkish forces. An initial area — where the population is primarily Arab rather than Kurdish — has been designated to begin the effort.

U.S. military officials have claimed “significant” progress, but Erdogan said this week that the effort was moving too slowly and that unilateral Turkish action remains an option if Turkey’s demands are not met by the end of the month.

Among the issues still in contention, both the United States and the Syrian Kurds have said initial refu­gee returns should include only Syrians who previously lived in the region, numbering significantly less than 1 million.