NEW YORK – Russia blocked a Western effort at the U.N. Security Council on Wednesday to condemn last week’s deadly gas attack in Syria and push Moscow’s ally President Bashar al-Assad to cooperate with international inquiries into the incident.

It was the eighth time during Syria’s six-year-old civil war that Moscow has used its veto power on the Security Council to shield Assad’s government.

In the latest veto, Russia blocked a draft resolution backed by the United States, France and Britain to denounce the attack in the town of Khan Sheikhoun and tell Assad’s government to provide access for investigators and information such as flight plans.

The toxic gas attack on April 4 prompted the United States to launch missile strikes on a Syrian air base and widened a rift between the United States and Russia.

Russian President Vladimir Putin said on Wednesday that trust had eroded between the two countries under U.S. President Donald Trump.

U.S. Secretary of State Rex Tillerson echoed that comment after meetings with Russian leaders in Moscow, saying that relations are at a low point with a low level of trust. Tillerson called for Assad to eventually relinquish power.

China, which has vetoed six resolutions on Syria since the civil war began, abstained from Wednesday’s U.N. vote, along with Ethiopia and Kazakhstan. Ten countries voted in favor of the text, while Bolivia joined Russia in voting no.

U.S. Ambassador to the United Nations, Nikki Haley, warned Moscow against protecting Assad, who relies on support from Russia and Iran.

Russia’s deputy U.N. envoy, Vladimir Safronkov, said the draft resolution laid blame prior to an independent investigation. During a heated Security Council exchange before Wednesday’s vote, Mr. Safronkov told the 15-member body that Western countries were wrong to blame Assad for the gas attack.

“I’m amazed that this was the conclusion. No one has yet visited the site of the crime. How do you know that?” he said.

He said the U.S. attack on the Syrian air base “was carried out in violation of international norms.”

The smuggling of sarin from Libya through Turkey on a civilian air plane by using a Syrian citizen. – Syrian U.N. Ambassador Bashar Ja’afari

Syrian Arab Republic Ambassador to the United Nations Bashar Jaafari arrives at a the Security Council meeting on the situation in Syria at the United Nations Headquarters in New York, U.S., April 12, 2017. REUTERS/Stephanie Keith

A fact-finding mission from the Organisation for the Prohibition of Chemical Weapons (OPCW) is investigating last week’s attack in a rebel-held area of northern Syria. If it determines that chemical weapons were used, then a joint U.N./OPCW investigation will look at the incident to determine who is to blame.

Syria’s government has denied responsibility for the gas attack in a rebel-held area of northern Syria that killed at least 87 people, many of them children.

Syrian U.N. Ambassador Bashar Ja’afari said Syria had sent dozens of letters to the Security Council, some detailing “the smuggling of sarin from Libya through Turkey on a civilian air plane by using a Syrian citizen.”

“Two liters of sarin were transported from Libya through Turkey to terrorist groups in Syria,” he said, adding that the government does “not have these weapons.”