Britain will send a team of experienced military officers to Libya to help support and advise the country's opposition council, the UK foreign minister has said.
William Hague said on Tuesday that military advisers would join a group of British diplomats already co-operating with the Libyan National Transitional Council, based in the rebel stronghold of Benghazi.
"They will advise the National Transitional Council on how to improve their military organisational structures, communications and logistics, including how best to distribute humanitarian aid and deliver medical assistance," he said.
However, the foreign office said the team would not train or arm rebel forces fighting troops loyal to Muammar Gaddafi, the Libyan leader.
He insisted that the deployment would be "fully within the terms" of the United Nations Security Council resolution on Libya, that authorised the set up of a no-fly zone over the country.
"Consistent with our obligations under that resolution, our officers will not be involved in training or arming the opposition's fighting forces," Hague said.
He did not specify when the military advisers would be sent but a statement from the foreign office said they would be deployed "quickly".
Britain had previously agreed to supply the rebels with telecommunications equipment and body armour to help them protect civilians.
The UN resolution does not provide for ground troops or any foreign occupation.
Earlier Catherine Ashton, the EU foreign policy chief, told Al Jazeera the bloc was looking at ways of sending troops to Libya on a humanitarian mission, if requested to do so by the UN.
"I've asked the European Union staff to work up a plan that would only rightly happen if, and it's a big if, the United Nations felt this was necessary."
She said these would not be combat troops "but people with expertise and experience who can go in and support the aid".
The NATO-led international operation to enforce the no-fly zone and protect civilians has been criticised by rebels in recent weeks for failing to do enough to protect them from attack by pro-Gaddafi forces.
On Tuesday, a member of Misrata's governing council, Nuri Abdullah Abdullati, called for British and French troops to be deployed to protect the besieged city, according to the AFP news agency.
"Previously, Abdullati told reporters, "we did not accept any foreign soldiers in our country, but now, as we face these crimes of Kadhafi, we are asking on the basis of humanitarian and Islamic principles for someone to come and stop the killing.
"Before we were asking for no foreign interference, but that was before Kadhafi used Grad rockets and planes. Now it's a life or death situation."
The military struggle for control of Libya has ground to a stalemate, with rebels backed by airstrikes apparently capable of holding their ground in the east of the country, while Gaddafi continues to control Tripoli and the west, apart from Misurata.
But Gaddafi's son, Saif al-Islam, told state television on Tuesday that he was confident the rebellion would fail.
"I am very optimistic and we will win," Saif said on Allibya television. "The situation changes every day in our favour.
Support for rebel council
Earlier on Tuesday, the leader of the Libyan Transitional National Council met Franco Frattini, Italy's foreign minister, to discuss the future of the country.
Mustafa Abdel Jalil said he would favour international ties "above all" with France, Italy and Qatar - the three countries that have recognised Libya's opposition, and that foreign policy would remain the same if it came to power.
But he said the way foreign revenue is distributed would change.
"There will be friendship and cooperation above all with Italy, France and Qatar," he said after talks with Frattini. "Our economic future will involve those who have supported us."
Frattini said Western and Middle Eastern states would meet in Rome next month to seek ways of realising oil revenue for the Libyan opposition.
UN sanctions, designed to constrain Gaddafi, have prevented rebels from selling oil to raise funds themselves. So far, the rebels have only been able to export small quantities of oil with the help of Qatar.
Frattini said Rome remained opposed to sending ground troops to Libya.
Death toll 'reaches 10,000'
Meanwhile Libya's opposition leaders said that at least 10,000 people had died since the start of the conflict in February.
Mike Hanna, Al Jazeera's correspondent in Benghazi, said: "Given the intensity of the conflict, it doesn't come as a surprise.
"We have focused on areas like Misurata, where the humanitarian crisis is well documented; however it is happening throughout Libya, the full extent of the crisis is not known and there is no real idea of [casualty] figures."
The United Nations says it has been guaranteed humanitarian access to Misurata, while Britain says it will fund efforts to evacuate thousands of stranded migrant workers by boat from the besieged port city.
A Libyan official told Valerie Amos, the UN humanitarian chief, that Gaddafi's government was willing to set up "safe passage" out of the city, which remains partially in opposition hands after weeks of attacks by loyalist forces.
Amos secured the deal through talks in Tripoli, apparently pledging to up the UN presence in the capital in return for humanitarian access in other Libyan cities.
But she said that while she had received assurances the UN would be able to access the city, she received "no guarantees" of a cessation of hostilities "to enable people to move" or for supplies to be delivered. Witnesses said government forces continued to pound the area with rockets and artillery.