European Union leaders meeting in Brussels are due to signal that new countries wanting to join the bloc will face a tougher examination than ever.
European Union leaders meeting in Brussels have reached a new consensus on the terms for accepting new members.
Draft conclusions of the EU summit in Brussels also say further expansion is dependent on the EU's ability to continue working effectively.
European Commission President Jose Manuel Barroso said applicants had to meet strict conditions, and the process depended on reform of EU institutions.
The leaders are said to have agreed that the EU's rulebook needs reforming.
Correspondents say this signals that countries wanting to join the bloc will face a tougher examination than ever.
They will also say the EU must do more to fight crime - but will not give up their veto in the area of home affairs.
However EU leaders have said there are no new criteria for membership and that the EU's doors are open.
The summit is also set to:
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Confirm
a slow-down in talks on Turkey's membership of the EU
Endorse
plans to increase sea patrols for the purpose of turning back African migrants
Accuse
Iran of destabilising the Middle East and condemn it for questioning the Nazi Holocaust
Express
deep concern about the deteriorating situation in Darfur
Endorse
a five-point Middle-East peace initiative
They also agreed that the EU must do more to fight crime - but failed to agree on the "institutional framework" for co-operation in this area.
The summit's draft conclusions put no new hurdles in the path of would-be members.
Some countries wanted to drop the national veto on police and judicial co-operation and to adopt policies in this area by majority vote, but the UK and some other states successfully opposed the move.
However, the leaders have said candidate countries must make progress on judicial reform and the fight against corruption earlier in the accession process.
The summit also:
class="bulletList">
Confirmed
a slow-down in talks on Turkey's membership of the EU
Endorsed
plans to increase sea patrols for the purpose of turning back African migrants
Accused
Iran of destabilising the Middle East and condemned it for questioning the Nazi Holocaust
Expressed
deep concern about the deteriorating situation in Darfur
Endorsed
a five-point Middle-East peace initiative
Treaty reform
Treaty reform
"To sustain the integration capacity of the EU the acceding countries must be ready and able to fully assume the obligations of Union membership and the Union must be able to function effectively and develop," the draft conclusions say.
"Past enlargements have been successful. Today we mapped out the best ways to ensure that future enlargements will also be successful," said Finnish Prime Minister Matti Vanhanen, who chaired the summit.
"It is important that the candidate countries meet the requirements and that the union is able to function effectively and to develop."
The draft conclusions do not explicitly say that further enlargement - after Bulgaria and Romania join on 1 January - is conditional on reform of EU institutions.
However, the UK's view that there should be "no automatic link" is not shared by all countries.
The summit's final statement was not expected to say explicitly that further enlargement - after Bulgaria and Romania join on 1 January - is conditional on reform of EU institutions.
Finnish Prime Minister Matti Vanhanen said there was a consensus for reform, but warned against throwing out the EU constitution, pointing out that 18 countries had ratified it.
However, Mr Barroso said institutional reform formed part of the consensus on enlargement - along with strict conditions for new members and better communication to convince citizens of its importance.
Mr Vanhanen said earlier that the leaders had agreed that EU treaties needed to be reformed, and that they could not "throw out the entire text" of the ill-fated European constitution.
Migration strategy
Migration strategy
Mr Vanhanen said member states had moved from a period of silent reflection after the French and Dutch rejections of the new constitution to what he called more active thinking.
This would be one of the main topics at an EU-Africa summit to be held in Lisbon in the second half of 2007, he said.
Finland will hand over the presidency of the EU to Germany in January, after which reform and a possible revival of the constitution are expected to be central issues.
The decision to drop from the draft statement all mention of removing the national veto on police and judicial co-operation was reportedly made at the insistence of the UK, Poland and the Czech Republic.
However, the draft statement still says that the "framework" for pursuing EU policies in this area needs to be strengthened.
In addition to endorsing extra sea patrols to locate migrants, EU leaders are also pledging a strategy on migration.
In addition to endorsing extra sea patrols to locate migrants, EU leaders are also pledging a strategy on migration.
Laws will be drafted to allow in skilled African workers and more aid measures to tackle African poverty.
Laws will be drafted to allow in skilled African workers and more aid measures to tackle African poverty.
