European Union leaders gathered on Thursday for a critical two-day summit focused on trying to find a solution to the euro zone debt crisis.

Following are highlights of comments from leaders and other senior officials as they arrived before an informal dinner to begin the summit:

BRITISH PRIME MINISTER DAVID CAMERON

These are important talks and we need obviously to get that stability in the euro zone that's good for European countries, good for Britain as well, but also we need to protect Britain's interests.

Those are my aims and that's what we'll be discussing.

GERMAN CHANCELLOR ANGELA MERKEL ON RESTORING EURO CREDIBILITY:

The euro has lost credibility and this must be won back. We will make clear that we will accept more binding rules.

The 17 members states of the euro have to make this clear and that means the Commission will get more responsibilities and the European Court of Justice will get more responsibilities.

That will make clear that in the future we will stick to the agreement of the Stability and Growth pact.

ON STABILITY AND FISCAL UNION:

We are making an important step towards stability and a fiscal union. The 17 countries have to do this in order to do a favor to all of Europe. Negotiations will show whether it will work on the basis of 17 plus x countries, or all of the 27.

It is important for me, as a result, that the euro can only regain its credibility by changing treaties to such an extent that we are moving towards a stability union.

That for me is central and I hope we can be successful.

ON MAKING PROGRESS:

Step-by-step we will approach the goal that unifies us. I think the member states that are not part of the euro have, just as much as those in the euro, a fundamental interest in the euro area working with more commitment and moving closer together towards a fiscal and stability union.

BELGIAN PRIME MINISTER ELIO DI RUPO

It's a very important European summit. The most important thing for Belgium is to find solutions for citizens and to have the European spirit and solidarity during this summit.

IMF MANAGING DIRECTOR CHRISTINE LAGARDE

We have a lot of work to do. It has to be coordinated, it has to be decisive, and the International Monetary Fund will participate in these efforts.

DUTCH PRIME MINISTER MARK RUTTE ON ENDING THE CRISIS:

What we have to do is to make sure that such crises can't reoccur in the future. We have to do everything to make sure that sanctions for countries that don't abide by the agreements are as automatic as possible.

At the same time we have to make sure that countries that are in trouble now will come up with a credible program to tackle these problems.

We have to make sure that we are ready to help such a country if they are under strong surveillance and such a program exists.

We also have to make sure that we keep the union of 27 together. It is not just a union of 17 euro countries. It is of great importance for a country such as the Netherlands, which is growth-orientated and believes in importance of jobs, that we keep countries such as the UK, Sweden and the Baltic countries and Poland in.

EUROGROUP PRESIDENT JEAN-CLAUDE JUNCKER ON CHANGING THE EUROPEAN UNION TREATY:

I would very much like if we managed a treaty change and an final agreement of the architectural foundations with 27 (EU member states). Should it turn out that not all 27 are able to go down this path, then we have to make a treaty change for the 17 euro states. I don't want this but I don't exclude it.

I'd like a treaty with 27 member states on board -- if that is not possible, with 17. I would not consider that, even though I would not like it, a dividing wall going through Europe.

The 17 member states are sharing a common currency. Their relationship is more intimate than between the 27.

ON PROPOSALS FROM FRANCE AND GERMANY:

I do think that the German and French proposals are pointing in the right direction, because these proposals in fact are the proposals some of us made months and months ago.

ON A BANKING LICENCE FOR ESM PERMANENT BAILOUT FUND:

That's a question we have to discuss quietly tonight. I don't want to commit to that before. I wouldn't mind but we will have to discuss that.

Other comments ahead of the summit:

VICKY FORD, CONSERVATIVE MEMBER OF THE EUROPEAN PARLIAMENT ON BRITISH APPROACH:

Within the area of financial services legislation, I think the UK should be focusing on avoiding EU 'one size fits all' legislation, which could limit the power of the UK's own regulators, as well as areas of legislation that would result in UK jobs relocating outside the EU, for example the financial transaction tax or bans on specific financial activities.

ON NEGOTIATING OPT-OUTS AND VETOES:

Opt-outs and vetoes in this area sound good for the UK given the weight of financial services to the British economy, but this would have to be very carefully negotiated.

If the cost of the UK getting an opt-out was to give all of the 27 different countries identical vetoes, then negotiating future legislation in this area could be chaos in getting cross-border agreements and undermine the single market.

I am not saying that the UK should have no veto on all financial 'rules'. The UK does have a veto on taxes, including the financial transaction tax.

The UK also has a specific opt-out from the Stability and Growth pact and therefore from the debt and deficit rules upon which it looks like any euro zone 'economic government' or 'fiscal government' is to be based.

(Reporting by Annika Breidthardt, Robert-Jan Bartunek, John O'Donnell, James Mackenzie and Christopher Le Coq)