Russia has lashed out over a U.S. charge that Moscow bears responsibility for the use of chemical weapons in Syria, and accused Washington of seeking to stymie efforts to end the war in the Middle Eastern country.

Russian officials responded angrily after U.S. Secretary of State Rex Tillerson said that Moscow "ultimately bears responsibility for the victims" of a new suspected chemical attack near Damascus.

President Vladimir Putin's spokesman, Dmitry Peskov, said on January 24 that U.S. officials were jumping to conclusions "without any grounds whatsoever."

"We categorically disagree with the approach of the Americans, who have essentially muddied the real investigation of previous instances" of Syria chemical attacks, Peskov told journalists.

Deputy Foreign Minister Sergei Ryabkov, meanwhile, claimed that the United States was attempting "to foment tensions and find pretexts for accusing Moscow of covering up instances of chemical-weapons use."

Syria's Foreign Ministry called claims that it was still using chemical weapons "lies" aimed at "obstructing any effort toward finding a way out of the crisis in Syria," according to state news agency SANA.

Russia has given President Bashar al-Assad's government crucial military and diplomatic support throughout the nearly seven-year war in Syria, which began with a crackdown on protests and has killed hundreds of thousands of people.

Western governments have long accused Moscow of using its clout as a veto-wielding UN Security Council member to protect Assad -- whom President Donald Trump has called a "criminal" -- from punishment for alleged chemical attacks and other actions.

In his remarks in Paris on January 23, Tillerson said that Russia was helping the Syrian government breach the Chemical Weapons Convention, which bans the use of the weapons.

"There is simply no denying that Russia, by shielding its Syrian ally, has breached its commitments to the United States as a framework guarantor" of a 2013 agreement on the removal of chemical weapons from Syria, Tillerson said.

He also said that Russia "must stop vetoing and at least abstain" in votes on future UN Security Council resolutions on holding the users of chemical weapons accountable.

Russia's ambassador to the United Nations, Vasily Nebenzya, angrily rejected Tillerson's charge, saying Washington had "hastily accused" the Syrian government of using chemical weapons.

"Now they are trying to drag Russia into this as well," Nebenzya told a UN Security Council session on January 23.

The Syrian Army and government have consistently denied using chemical weapons during the war, now in its seventh year, while Moscow says extremists have used chemical weapons in the past.

UN efforts to sanction perpetrators of chemical attacks have failed, repeatedly blocked by Russia.

Tillerson was speaking at a conference of a new organization, the International Partnership against Impunity for the Use of Chemical Weapons, that intends to step up pressure on the perpetrators of chemical attacks.

The French Foreign Ministry said the new group "in no way intends to replace existing international mechanisms, nor does it plan to conduct its own investigations."

But the initiative drew vocal objections from Russia, with Ryabkov calling it "a direct encroachment on the prerogatives of the Organization for the Prohibition of Chemical Weapons and a blow to the UN platform."

Activists and rescue teams said the Syrian government is suspected of using poisonous gas that affected nearly 20 civilians in a rebel-held suburb near Damascus on January 22.

With reporting by AP, AFP, Reuters, TASS, and Interfax