US must not act on fabricated pretexts in Syria: Moscow

Moscow today warned the United States against carrying out a "military intervention on fabricated pretexts" in Syria, insisting that the Damascus regime did not use chemical weapons on an opposition holdout in Eastern Ghouta.

"We must once more warn that a military intervention under far-fetched and fabricated pretexts in Syria, where there are Russian soldiers at the request of the legitimate Syrian government, is absolutely unacceptable and could have the most dire consequences," the foreign ministry said in a statement.

Released before Donald Trump called Syrian President Bashar al-Assad an "animal" and warning that there would be a "big price to pay" for what the US president called a "mindless chemical attack", the ministry called the allegations "provocations".

The rebel holdout of Douma in eastern Ghouta near Damascus was pounded Friday and Saturday by renewed airstrikes that killed at least 80 people, with first responders accusing forces loyal to Assad of using poisonous chlorine gas in the attacks, claims denied by state media.

"The goal of this speculation... is to cover for the terrorists and the radical opposition who are rejecting a political settlement" to Syrias seven-year war, the Russian foreign ministry said.

Earlier, Major General Yuri Yevtushenko, head of the Russian Center for Reconciliation of the Warring Sides in Syria, denied the allegations against the Assad regime.

"We are ready, once Douma is freed from militants, to immediately send Russian specialists in radiation, chemical and biological defence to collect data that will confirm these claims are fabricated," he said, quoted by news agencies.

The White Helmets, who act as first responders in rebel-held areas of Syria, along with an insurgent group and the opposition in exile, accused the Syrian government of carrying out a chemical attack.

In a joint statement, the White Helmets and the humanitarian group Syrian American Medical Society (SAMS) said 48 people were killed.

The Syrian Observatory for Human Rights, a Britain-based monitor, reported dozens of cases of suffocation, some of them fatal, without saying whether chemical weapons were involved.

"These reports, if confirmed, are horrifying and demand an immediate response by the international community," US State Department spokeswoman Heather Nauert said in a statement earlier.

"The Assad regime and its backers must be held accountable and any further attacks prevented immediately," she added.

"Russia, with its unwavering support for the regime, ultimately bears responsibility for these brutal attacks."

The Syrian regime has been repeatedly accused of using chemical weapons, with the United Nations among those blaming government forces for a deadly sarin gas attack on the opposition-held village of Khan Sheikhun in April 2017.

Since February 18, the regimes Ghouta offensive has killed more than 1,600 civilians.

The regime has used a combination of a fierce military onslaught and two negotiated withdrawals to empty out 95 percent of the enclave near Damascus, but rebels are still entrenched in Ghoutas largest town of Douma.