The Syrian regime and its Russian and Iranian backers have vowed to keep up the fight against "terrorists" despite threats of further USA strikes against the regime following the chemical attack.
Lavrov pointed out that "an attack on a country whose government fights terrorism only plays into the hands of extremists, creates additional threats to regional and global security", the Russian ministry said.
Sir Michael Fallon said Vladimir Putin's Kremlin was to blame "by proxy" because it was the Syrian president's "principal backer".
Syria: What led to the U.S. air strikes? "They are repeating offense of their predecessors", Khamenei was quoted as saying by the official IRNA news agency. Russian Federation is the Syrian regime's main ally in the nation's six-year-long civil war.
Johnson added, "We deplore Russia's continued defense of the Assad regime even after the chemical-weapons attack on innocent civilians".
Assad's government has denied any involvement in the attack in the town of Khan Sheikhoun in the rebel-held Idlib province.
Pope on Palm Sunday decries suffering from war, terrorism
On Saturday, April 29, Pope Francis will celebrate Mass in the morning, followed by a meeting with Egypt's bishops over lunch. ISIS claimed responsibility for the attacks occurring a week before Coptic Easter. "I pray for the dead and the victims.
The comments represented a departure from what Haley had said before the United States hit a Syrian air base with 59 Tomahawk missiles on Thursday in retaliation for what it said was a chemical weapons attack by Assad's forces on Syrian civilians.
The SNP's foreign affairs spokesman said the move makes Mr Johnson look like "some sort of mini-me" who can not be trusted to hold his own talks with Russian counterpart Sergey Lavrov. This statement comes after the U.S. launched 59 Tomahawk missiles at the Shayrat Airbase in response to the Assad regime's alleged use of chemical weapons in the Idlib region.
But Sir Michael said the launching of nearly 60 missiles at the regime airbase from which the attack is said to have originated would now make future incidents less likely.
The top priority for the United States in Syria is to defeat Daesh, said Secretary of State Rex Tillerson said at a TV interview on Sunday. Turkey provides military support to some of Syria's opposition forces.
"If we can achieve ceasefires in zones of stabilization in Syria, then I believe - we hope we will have the conditions to begin a useful political process", Tillerson said.
British Foreign Secretary Boris Johnson cancelled a visit to Moscow, scheduled for April 10, after the poison gas attack in Syria.