Speaking from Istanbul, Mr Hague said the country stood “on the brink” of civil war and did not rule out military intervention.
“My meetings with the Syrian opposition and the Turkish foreign minister were important and timely in the light of the sickening murders at el-Houla and other parts of Syria,” he said.
“We discussed the desperate need for a political solution in Syria and the importance of implementing the Annan Plan in full to ensure that a political transition happens quickly.”
It came after peace envoy Kofi Annan spoke of his frustration after the deadline given to President Bashar Assad by the Free Syrian Army to comply with the United Nations’ peace plan expired.
Amid mounting fears of a full civil war, Mr Annan told a press conference it was the role of the UN Security Council to decide what other measures should be implemented in the country.
“What is important is that we continue our efforts to find a solution that leads to a democratic transition in Syria, that fulfils the aspirations of the Syrian people,” he said.
“I know we are all impatient, we are all frustrated by the violence, by the killings.
“So am I. I think perhaps I’m more frustrated that most of you, because I’m in the thick of things and would really want to see things move much faster than it has done.”
Video had emerged earlier of another alleged mass killing in the country.
The opposition claimed 13 men were on their way to work at a state-owned fertiliser factory in Qusair – near the city of Homs – when they came under fire.
Rebels had warned of violent retaliation if the regime failed to stop attacking towns and cities by 10am London time today.
In a statement posted on YouTube, Colonel Qassim Saadeddine of the Free Syrian Army said there was “no justification” in only one side respecting the truce.
“The Annan plan arrived in Syria and Assad buried it in front of the world by committing massacres in Houla, Homs and Hama, Allepo, Deraa and Deir al Zour, Damascus, Idlib and Tartous and Latakia,” he said.
“The joint command of the free army inside Syria… issues an ultimatum of 48 hours to respect the UN Security Council resolution and international legitimacy immediately by ending all forms of violence, as well as pulling out tanks and military vehicles from towns and villages and allowing the entrance of humantiarian aid.”
The warning came after 13 bodies were found by UN observers near Assukar, in an earlier and separate alleged massacre to that said to have been committed near Homs. Their hands had been tied and some had apparently been shot through the head.
A senior official from the Assad regime told a press conference in Damascus the Houla massacre was carried out by “armed groups” and not by government forces as has been widely claimed.
“It appears that the all the victims came from peaceful families who refused to rise up against the government or take up arms, but had rows with armed groups,” claimed General Kassem Jamaleddine, chief of the inquest into the incident.
Many of the victims were women and childen who had been summarily executed, according to the United Nations.
Rebels have said they were civilians on their way home from work at a factory when they were stopped at a checkpoint and shot.
Meanwhile, the UN’s top human rights advisor Navi Pillay has said that without an effective peace plan Syria would descend into civil war.
In another development, Syria’s honorary consul general in the US resigned over the massacre of 108 civilians in the town of Houla over the weekend.
California-based Hazem Chehabi was one of Syria’s highest-ranking diplomats in the States and is the first to defect from President Assad’s regime.
Kofi Annan at a news conference in Damascus after his meeting with Syrian President Bashar Assad
“You get to a point where your silence or your inaction becomes ethically and morally unacceptable,” he told NPR’s Morning Edition.
“The recent barbaric massacre that took place in the town of Houla, for me it was a tipping point and was a point beyond which one could not justify remaining silent,” he added.
Mr Chehabi’s resignation follows the US decision to expel Syria’s top diplomat in Washington after what it described as the “despicable” killings in Houla.
UN-Arab League peace envoy Mr Annan, who had “frank” talks with President Assad in Damascus on Tuesday, said those responsible must be held to account.
He has urged “everyone with a gun” to abide by his six-point blueprint to help end 15 months of bloodshed in the country.
Some 49 children and 34 women were killed in the Houla massacre, many of them blown to bits or shot dead at point blank range.
The UK-based Syrian Observatory for Human Rights says more than 13,000 people have died since the revolt against president Assad’s regime began in March last year.
Source: Sky News