David Cameron praised the bravery of UK military forces in action over Libya today as he insisted the campaign would continue until civilians were "safe and secure from attack".
The Prime Minister said the coalition had been right to act "quickly and decisively", but the situation remained "grave" in Misurata and Zintan.
British forces had now carried out 70 sorties against Muammar Gaddafi's troops, including striking at tanks on the ground, he said.
"I want to thank all of those involved for their incredible skill and bravery," Mr Cameron told journalists in Brussels. "The situation of civilians in Misrata and Zintan is grave. But we have moved quickly and decisively over the last week and I think it was right to do so."
Mr Cameron said the EU summit had agreed that "military action should continue until people are safe and secure and until UN Security Council Resolution 1973 is properly implemented".
Moves to put Nato in charge of enforcing the no-fly zone over Libya were "an important step forward", he added.
Mr Cameron again urged Col Gaddafi to go and his "henchmen" to desert.
"My message to Gaddafi, in absolute co-ordination with what Hillary Clinton has said, is that he should leave, he should go.
"I don't believe there is any future for Libya and the Libyan people with him at its helm, so he should go," the Prime Minister said.
"And the message also to those around him, is that every day you work with this dictator - who has now announced two ceasefires and broken both of them, and continues to murder his own civilians - every day you work for him you are at risk of the International Criminal Court and you are at risk of being found guilty of war crimes.
"The people who are around him and are obeying his orders should realise that that time is up. Don't obey his orders, walk away from your tanks, leave the command and control that you are doing, give up on this regime because it should be over for him and his henchmen."
The Ministry of Defence said Col Gaddafi was continuing to inflict "deadly and indiscriminate" attacks but that coalition forces were steadily destroying his aircraft, tanks and guns.
"It's very clear that, despite the heavy losses inflicted on his forces by coalition operations, Colonel Gaddafi continues to flout the will of the international community and is continuing to mount deadly and indiscriminate attacks on his own people," spokesman Major General John Lorimer said.
"But it is equally clear that our operations have saved many innocent lives already and we are confident that they will continue to do so."
Maj Gen Lorimer, chief spokesman for the Chief of the Defence Staff, said Nato was expected to take overall command within a matter of days.
"Attacks on the integrated air defence system, whether from Tomahawks or aircraft, have reduced the threat from Colonel Gaddafi's surface-to-air missiles to a negligible level," he went on.
"It is significant that we have not detected any attempts at engagement by such systems since the start of our air operations.
"Coalition air sorties have therefore been able to focus on finding, and where necessary attacking, targets such as the regime's armoured and mechanised forces, artillery batteries and shorter-range mobile missile batteries.
"We have not been able to stop all of Colonel Gaddafi's attacks, but we would never pretend that we could.
"But every day that he continues to defy UNSCR 1973 his forces suffer the consequences.
"They are losing aircraft, tanks and guns that they cannot replace. His ability to use these weapons against his own people is diminished daily."Reuse content