JOIN USIntense battle raged around the key town of Misurata and Ajdabiya, as rebel forces were making last ditch efforts to stop two tanks-led columns closing on the two port cities of Benghazi and Tobruk, which would give the Libyan leader total sway over his country.
Al Jazeera quoted state-run Libyan television as saying that forces loyal to the strongman Gaddafi were on the outskirts of Benghazi.
"The town of Zuwaytinah is under control (of loyalists) and armed forces are on the outskirts of Benghazi," the Arab channel said.
Wary of the speed at which Gaddafi's forces were moving, the White House set a sort of a deadline of tonight for an international response in Libya as a top US official said
Washington was contemplating steps that include but perhaps go beyond a 'no fly' zone.
As intense battles raged, the UN Security Council is to meet tonight to vote on a draft resolution that would not only introduce a no 'fly zone' over Libya, but may also authorise the use of air strikes to stop the advance of Gaddafi's forces.
Susan Rice, US ambassador to the UN, said: "We are discussing very seriously and leading efforts in the Council around a range of actions that we believe could be effective in protecting civilians".
Claiming that Gaddafi forces seemed determined to kill as many Libyans as possible, she said "many different actions" were being considered.
Top US officials said military action could be directed not only at Gaddafi's air force, but at artillery and communications systems too, apparently hinting that heavy western air strikes may be in the offing.
The change in the US mood appeared to be drives by the worsening plight of the rebels, with TV footage showing that lightly armed rebels were being pummeled by Gaddafi's forces.
Apprehending a combined western move against him under the aegis of the UN Security Council, Gaddafi's son Saif al-Islam has set a "48 hours" deadline for his forces to capture the twin cities of Benghazi and Tobruk.
Facing an unprecedented uprising against his 41-year-old rule, Gaddafi unleashed his forces to wrest back territories seized by the rebels, Al Jazeera channel said.
The battle appeared to be uneven as TV channel showed burnt out vehicles of the rebel forces in a roadside just outside Ajdabiya, while Libyan government forces displayed tanks, artillery guns, mortars and mobile rocket launchers, much heavier weapons than used by the opposition forces.
The western powers apprehend that Gaddafi's forces would use fighter jets to bombard urban areas of Benghazi.
Martin Nesirky, a spokesman of Ban Ki-moon, said the secretary-general was "gravely concerned" about signs that Gaddafi was preparing to attack Benghazi.
"A campaign to bombard such an urban centre would massively place civilian lives at risk," he said.