BEIRUT (AP) -- British Foreign Secretary Boris Johnson says the alleged chemical attack near Idlib in Syria "bears all the hallmarks" of the Syrian government.
Johnson said in a statement Tuesday that he was "horrified," at the reports of the attack and said Bashar Assad's government has repeatedly used chemical weapons in the past.
His comments followed reports from the Britain-based Syrian Observatory for Human Rights, which put the death toll from the attack at 58.
Johnson says his government "will continue to lead international efforts to hold perpetrators to account."
Britain is urging Russia and China not to block action against those responsible for a suspected chemical attack in Syria's rebel-held Idlib province which it is calling "a war crime."
Britain and France have called for an emergency meeting of the U.N. Security Council, which is scheduled to hold its monthly meeting on Syria's chemical weapons on Wednesday. Diplomats said that meeting could be moved up to later Tuesday.
Britain's U.N. Ambassador Matthew Rycroft said the attack earlier Tuesday "has all the hallmarks of a regime attack" because the Syrian government is the only party to the conflict equipped to deliver deadly chemicals.
Rycroft called the attack "clearly a war crime" and indirectly criticized Russia and China for protecting Syria by vetoing previous council resolutions.
The ambassador said he hoped for a different approach from "the Security Council members who have previously used their vetoes to defend the indefensible."
Rycroft said an emergency council meeting would "shine a spotlight on the heinous use of chemical weapons yet again" in Syria, rally support for action in the council, and put pressure on Russia and China "to hold to account those who used chemical weapons."
United Nations Syria envoy Staffan de Mistura is calling for the perpetrators of a suspected chemical attack in a northern province to be held accountable for the "horrific" attack.
De Mistura called Tuesday for "clear identification of responsibilities and accountability."
Speaking on the eve of a conference on Syria's future, he said "every time we have a moment in which the international community is capable of being together - 70 countries tomorrow - there is someone, somehow, that tries to undermine that feeling of hope by producing a feeling of horror and outrage."
But, he added, "we are not going to give up."