British Foreign Secretary William Hague says his country will provide body armor and armored vehicles to Syrian rebels who are battling President Bashar al-Assad's forces.
Hague told parliament that the "nonlethal" military aid, worth $20 million, was a "necessary, proportionate and lawful response" to a situation of "extreme" humanitarian suffering.
Britain has already provided opposition forces with equipment such as power generators and communications devices worth more than $14 million.
But Hague said the British government was being forced to move toward "more active efforts" to support opposition forces.
"Diplomacy is taking far too long and the prospect of an immediate breakthrough [in Syria] is slim," Hague said. "Each month of violence in Syria means more death, wider destruction, larger numbers of refugees, and bloody military confrontation. The international community cannot stand still in the face of this reality. Our policy has to move towards more active efforts to prevent the loss of life in Syria, and this means stepping up our support to the opposition."
The announcement comes after the European Union last week authorized the supply of nonlethal military equipment and training to the Syrian opposition.
Hague also said other types of support should be considered as well if diplomacy fails to stop the bloodshed.
"In our view, if a political solution to the crisis in Syria is not found and the conflict continues, we and the rest of the European Union will have to be ready to move further and we should not rule out any option for saving lives," he said.
U.S. Secretary of State John Kerry announced last month that Washington was pledging $60 million in funds for Syria's political opposition, as well as food and medical assistance.
According to United Nations estimates, the two-year conflict has caused at least 70,000 deaths.
The UN on March 6 said more than 1 million Syrians also have fled their homeland to escape the fighting.
In a statement, UN High Commissioner for Refugees (UNHCR) Antonio Guterres said about half of Syria’s refugees are children.
With millions more displaced inside Syria, Guterres warned that the country is "spiraling towards full-scale disaster."
The UNHCR says the growing number of refugees is severely straining the resources of host countries.
Most Syrian refugees have fled to Lebanon, Jordan, Turkey, Iraq, and Egypt.
Meanwhile, the United Nations says about 20 UN peacekeepers have been detained by armed fighters in the Golan Heights on the border between Syria and Israel.
UN deputy spokesman Eduardo del Buey says the group was detained by about 30 armed men and that the UN has sent a team to resolve the situation.
The confirmation came after a video was posted on YouTube purporting to show Syrian rebels with the seized UN convoy.
In the video, a young man claiming to be from the "Martyrs of Yarmouk" brigade says the convoy will not be released until Syrian government forces withdraw from a village in the area.
Israel captured the Golan Heights from Syria in a 1967 war. Syrian troops are not allowed in the area of separation and the zone is patrolled by UN peacekeepers.
With reporting by AFP, AP, Reuters, and the BBC