Europe must be "ready to act" if the situation in Libya deteriorates, Prime Minister David Cameron said today.
Speaking at the end of an emergency summit in Brussels, Mr Cameron said the EU's 27 leaders were "united, categorical and crystal-clear" that Libya's dictator Muammar Gaddafi must go.
He said it appeared that the situation of the opposition forces seeking to oust Gaddafi was getting "worse, not better", and warned that "horrors" may have been committed by the dictator's forces away from the eyes of the world.
Today's summit agreed new sanctions against financial institutions linked to the Gaddafi family and agreed that contingency planning must be continued on possible further action, including a no-fly zone to stop air attacks on rebel forces and civilians.
At a press conference concluding the summit, Mr Cameron said he had discussed the possibility of a no-fly zone with US President Barack Obama and France's President Nicolas Sarkozy.
"We are clear that action must be necessary, legal and win broad support," he said.
"But we must be ready to act if the situation requires it. Today, the EU agreed to consider all necessary options when it comes to these eventualities."
He added: "Today, EU leaders were united, categorical and crystal-clear - Gaddafi must go.
"We also agreed to tighten the net on him and his henchmen, so we have strengthened the financial sanctions on the regime, adding the Libyan Central Bank and Libyan Investment Authority to the EU asset-freezing list.
"In doing so, the UK has frozen a total of £12 billion of Libyan assets."
Mr Cameron described the situation in Libya as dangerous: "We are witnessing what can only be called barbaric acts, with Gaddafi brutally repressing a popular uprising led by his own people and flagrantly ignoring the will of the international community, and ... things are getting worse, not better, on the ground."
Recalling Gaddafi's record of supporting terrorism - including the Lockerbie bombing - and flouting the will of the international community, the Prime Minister warned: "If we don't sort out the current problems, the risk is again of a failed pariah state festering on Europe's southern border, threatening our security, pushing people across the Mediterranean and creating a more dangerous and uncertain world for Britain and her allies.
"That is what we must avoid and that is why this matters."
Mr Cameron said that the international community had acted swiftly to agree a UN Security Council resolution condemning Gaddafi's violence against his own people, to freeze his regime's assets and to initiate an investigation by the International Criminal Court.
But he added: "Gaddafi is still on the rampage, waging war on his own people. Hundreds of thousands have been displaced and right now there is no sign of this ending.
"Round the region, people continue to campaign for change and their aspirations have not yet been met.
"Britain should be a relentless advocate for greater political openness, support for human rights and non-violence. In the long term, that's the way to get stability and prosperity to this region.
"But we can't do this alone. The international community must be ready to act if the situation requires it.
"We simply don't know how bad this could get or what horrors already lie hidden in the Libyan desert.
"There is still a huge job to be done, but I am determined that Britain will play its part."
Mr Cameron said that the EU must do its part to encourage a move to more open, democratic societies throughout the Middle East and North Africa, by making access to European markets and the billions of euros supplied under so-called Association Agreements with its neighbours conditional on the delivery of reform.
"This is not some far-flung part of the world," he said. "North Africa is only a few miles from southern Spain. What happens there has a direct impact on Europe and it is in our national interest to help shape these momentous events.
"Greater openness in the region will in the long term, I believe, lead to stability and economic success, so Europe needs to seize and shape this moment. With this long-term agenda, Europe can make a difference.
"I argued today for a fundamental transformation in the EU's approach. We must encourage change, we must apply a greater conditionality to the billions of euros we spend and we must make a real and credible offer to those countries based around co-operation with Europe."
Today's meeting saw only "a first discussion" on the long-term future of the EU's relations with its neighbours, said Mr Cameron.
But he added: "It is clear that we need to overhaul our approach and make the most of the economic incentives we offer. Europe has a real role here and I am determined we should play it."
The Prime Minister denied being "frustrated" that today's communique did not refer to a no-fly zone. He stressed that the EU had agreed to consider "all necessary options".
"I think it is progress but sometimes progress can take some time when you have got 27 conversations around the table," he said.
"But I think 'all necessary options" is pretty tough when it comes to these dreadful events that are happening in Libya."
Mr Cameron said "words are not enough" and insisted the international community had to be ready to act.
"What we need to do now is start the planning and the preparation so that if it's necessary to act that we can act," he said.
"Of course, in the end words are not enough, in the end what we will be judged on is our actions.
"But has the international community come together and come together rapidly in order to isolate the regime and put in place a tough approach?
"Yes it has, and a lot of that is down to the role Britain has played."
He added: "This man is brutalising his own people and we can't stand by while that happens.
"Clearly every day he (Gaddafi) goes on brutalising his own people is a bad day for humanity, is a bad day for people in Libya, and we should be standing with those people who want a better future for Libya, and that future cannot include Colonel Gaddafi."
The Prime Minister said the international community had to consider the consequences of failing to prevent the genocides in the former Yugoslavia and Rwanda.
"Many people say we have to learn the lesson of Iraq, and yes we do, but we also have to learn the lesson of what happened in the former Yugoslavia, in Bosnia, as well."
He added: "We also have to learn the lesson of what has happened in other parts of the world, where there might have been talk but there wasn't action when it was necessary and I do think we have to think about that as we go ahead."Reuse content