Nations urging the UN to ban helicopter sales to Syria and impose other sanctions over chemical weapons use are seeking a Security Council vote next week, saying the body needs to take action after attacks the U.S. envoy called "barbaric." But Russia is vowing a veto.

A Security Council diplomat said Friday night that the vote was requested for next week. The diplomat spoke on condition of anonymity because discussions about the request were private. Britain's deputy UN ambassador, Peter Wilson, had said earlier Friday that a vote would come "as soon as possible."

Britain, France and the United States have been seeking sanctions after an investigation by the United Nations and an international chemical weapons watchdog organization determined last year that the Syrian government was behind at least three attacks involving chlorine gas in the civil-war-ravaged country. The probe also found the Islamic State group was responsible for at least one involving mustard gas.

President Bashar Assad's regime denies using chemical weapons in the war, which has killed hundreds of thousands of people and displaced millions since it began in March 2011. Russia, Syria's closest ally, has questioned the investigation's conclusions linking chemical weapons use to Syrian government, and Russian deputy ambassador Vladimir Safronkov said Friday that his nation would veto the sanctions measure if it came up for a vote.

"It's a provocation," he said outside after leaving a closed-door Security Council session about Syria.

In a sharp retort, U.S. Ambassador Nikki Haley said the measure "needs to happen."

"How much longer is Russia going to continue to babysit and make excuses for the Syrian regime?" she said. "People have died by being suffocated to death. That's barbaric."

The remarks were the latest signals that new President Donald Trump's administration aims to confront Russia on some issues, while also expressing interest in improving relations. Earlier this week, Haley reiterated that U.S. sanctions on Russia over its 2014 annexation of Ukraine's Crimean Peninsula will continue until the region is returned to Ukraine.

Despite the promised Russian veto, backers of the proposed UN sanctions see them as a moral and institutional imperative. Previous council resolutions called for "measures," under a UN charter chapter that authorizes sanctions, if chemical weapons are used.

"On the scale of the threats to peace and security, we are at 10 here," French Ambassador Francois Delattre said before Friday's meeting.

"If the Security Council is not able to unite on such a literally vital question of proliferation and use of weapons of mass destruction against civilian populations, then what? So what is at stake here, frankly, is the credibility of the Security Council," he said.

The movement toward a vote is coming at a delicate time. Peace talks began Thursday in Geneva, with the UN envoy for Syria casting them as a historic chance to end the conflict.

Besides the prohibition on helicopter sales, a draft of the sanctions resolution seen by The Associated Press would impose an asset freeze and travel ban on 11 Syrian people.

They include current and former military officers, the managing director of a Ministry of Defence subsidiary and the director-general of Syria's Scientific Studies Research Center, according to the draft. It says the research centre was responsible for the development and production of chemical weapons.

The asset freeze also would apply to the research centre, to eight entities described as its front companies or proxies and to the Ministry of Defence subsidiary.

There was no immediate response to an inquiry Friday to the Syrian mission. Syria isn't a Security Council member.

The U.S. imposed its own sanctions in January on Syria's military and some officials.

A chemical weapons attack on a Damascus suburb killed hundreds of civilians on Aug. 21, 2013, leading to a U.S.-Russian agreement and a Security Council resolution the next month ordering the destruction of Syria's chemical weapons, precursors and the equipment to produce the deadly agents.

The Syrian government's support for the resolution and decision to join the chemical weapons watchdog, known as the OPCW, warded off possible U.S. military strikes in response to the attack, which the Syrian regime denied carrying out.

Syria's declared stockpile of 1,300 metric tons of chemicals has been destroyed, but the OPCW has continued to investigate outstanding questions about possible undeclared chemical weapons.