Brussels, June 16 (DPA) European Union leaders delayed a decision on the fate of the bloc's crippled constitution until the end of 2008, highlighting deep divisions within the 25-nation bloc on whether to bury or resurrect the treaty.

Austrian Chancellor Wolfgang Schuessel, whose country currently holds the rotating EU presidency, admitted Thursday the 25 leaders had failed to reach consensus on the future of the failed treaty which was resoundingly rejected by French and Dutch voters last year.

"Nobody felt that a rapid solution is in sight today," Schuessel told reporters at the end of the first day of the summit.

But no EU leader had said the ratification process should be broken off, he said.

Given continuing disagreements, Schuessel said that leaders had agreed to continue the "process of assessment until at the latest at the end of 2008".

A communique by the 25-nation bloc, to be issued on Friday, calls for extending a so-called "pause for reflection" through June 2007, with final decisions on the treaty's fate put off until the end of 2008.

The statement said Germany, which holds the EU's rotating presidency in the first half of 2007, would issue a report on the "state of discussion" on the treaty which will "explore possible future developments".

Recognising that reviving the treaty - if this is possible - will be a long haul effort, leaders set no firm deadline for when the treaty would come into force.

This appeared to be a step backwards compared to calls from EU foreign ministers last month for the constitution to be approved and up and running by 2009.

Schuessel and EU Commission President Jose Manuel Barroso said leaders would focus on a "double-track approach" which would include efforts to deliver concrete results on issues like immigration and energy while working on constitutional reform.

A total of 15 of the 25 EU states have given a green light for the constitution, mainly through parliamentary ratification. All 25 must approve the treaty for it to enter into force.

Given that the last 12 months have produced little more than hand-wringing over the constitution's fate, there is no guarantee that another year will be more productive.

"The period of reflection begun a year ago has ended without producing any consensus of the constitutional treaty, nor has any plan B been found," said European Parliament President Josep Borrell.

To tide over - and produce a feel-good momentum - EU leaders will issue a "political declaration" on their "values and ambitions" at a summit in Berlin in March next year to mark the 50th anniversary of the EU's founding with the Treaty of Rome.

German Chancellor Angela Merkel has been outspoken with calls to preserve most of the original constitutional treaty text.

But Dutch Foreign Minister Bernard Bot insists the constitution be radically slashed in scope and downgraded to a mere treaty status. This would allow it to be approved by the Dutch parliament and prevent it from facing another referendum.

Turning to the other key issue at the summit, Schuessel denied the EU was setting up new obstacles to further expansion of the bloc.

"We do not set up new criteria. We always said the candidates must be prepared ... to meet their responsibilities," he said.

But in a sign of a deep split on the issue, Swedish Prime Minister Goran Persson insisted he would veto any EU moves to raise new barriers by references to the bloc's "absorption capacity" before further enlargement.

"I am dead against it," said Persson.

French President Jacques Chirac and some of the old EU states insist that opening of the bloc's doors to poorer cousins of south-east Europe must hinge on whether old members are capable of dealing with them and paying what are expected to be massive bills for developing their infrastructure.

Bulgaria and Romania will join the EU either in 2007 or 2008, but after that it remains unclear as to when the bloc will take in aspiring states such Croatia and other countries in the western Balkans.

Further afield, both Ukraine and Georgia are knocking at the EU door. Membership talks with Turkey, which were agreed to last October, are expected to last up to 15 years.

Linking the constitution and enlargement, European Commission President Jose Manuel Barroso has warned that the EU cannot enlarge further - after taking in Romania and Bulgaria - unless a new institutional and decision-making framework is in place.

The 2001 Nice Treaty - under which the bloc now functions given failure to ratify the new constitution - only has provisions for an EU of 27 states.

In other summit business, leaders discussed the bloc's immigration crisis following the arrival of thousands of illegal migrants from Africa on Spain's Canary Islands over the past weeks.

They also will nod through Slovenia's planned membership in the eurozone as of Jan 1, 2007, and are expected to confirm the rejection of Lithuania's bid to also adopt the euro.