The U.N. General Assembly late Tuesday adopted a resolution critical of the human rights situation in Syria, embroiled in a civil conflict entering its 20th month.
Hague said he welcomed the resolution that condemned alleged abuses by both sides of the conflict. All sides are called on to lay down their weapons, though Hague stressed it was the Syrian government's responsibility to end attacks on the civilian population.
"The widespread and systematic human rights violations being committed by the Syrian regime and its militia are absolutely appalling and deserve the strongest condemnation," he said in a statement.
Human Rights Watch this week reported that pro-government forces used cluster bombs in an attack near Damascus that left at least 10 children dead.
The British government last week recognized the National Coalition of Syrian Revolutionary and Opposition Forces, an opposition council formed mid-November in Qatar, as the legitimate representative of the Syrian people.
"I call on all sides to put an end to the violence and to pursue a process of genuine political transition to meet the demands of the Syrian people for a free Syria," said Hague.