|Thursday's announcement came after Jalil's first official talks with the British prime minister [Reuters]
David Cameron, the British prime minister, has invited leaders of the Benghazi-based Libyan opposition to open formal offices in London.
He made the announcement following talks with Mustafa Abdul Jalil, chairman of the National Transitional Council in the British capital on Thursday.
"These steps continue our very clear intention to work with the council to ensure Libya has a safe and stable future, free from the tyranny of the Gaddafi regime," Cameron said.
He added that the UK presence in Benghazi, Libya's rebel stronghold, would also be boosted, and that Britain will supply police officers there with uniforms and body armour.
Jalil is to meet William Hague, the UK's foreign minister, and George Osborne, the finance minister, later in the day.
Catherine Ashton, the EU foreign policy chief, also announced plans to open an office in Benghazi to facilitate assistance to the rebel council based there.
"I intend to open an office in Benghazi so that we can move forward on the support we've discussed to the people... to support civil society, to support the Interim National Transitional Council," Ashton told the European Parliament.
She said EU support would include help for security sector reform and institution-building.
"We want to help with education, with health care, with security on the borders," she said.
Members of the NATO-led coalition enforcing a no-fly zone over Libya met last week to discuss setting up a fund to help forces fighting the government of Muammar Gaddafi, the north African nation's leader.
A fund controlled by France, Italy and Qatar - the first countries to recognise the Transitional National Council - was announced with donations from other countries including Kuwait.
The US has said it is looking at ways to free up some of the $30bn Libyan assets it has frozen to aid opposition forces, who say they need food, humanitarian and medical supplies urgently.