The European Union has told Ukraine it is not ready to join the bloc.
Ukraine is promised enhanced EU co-operation
EU Commission President Jose Manuel Barroso said more reforms were required before accession talks could begin.
Ukraine's president Viktor Yushchenko met EU leaders in Finland, trying to push the case for membership talks to start by 2008.
He assured EU leaders of energy supplies over the winter, following last year's brief cut in natural gas flows after a price row with Moscow.
Mr Yushchenko has sought closer ties with the West since coming to power in the Orange Revolution of 2004.
But a BBC correspondent in Ukraine says the EU is concerned that reforms are being slowed by political divisions.
Ukrainian Prime Minister Viktor Yanukovych is a fierce rival of the president and favours ties with Russia over those with the EU.
The EU has repeatedly told Ukraine that membership is not up for consideration at the moment.
"Ukraine is not ready and we are not ready," Mr Barroso said after meeting President Yushchenko.
"Ukraine still has reforms to do... and today in the European Union we are not ready, our member states are not ready, to assume new membership obligations," he said.
Instead, EU leaders are offering the prospect of closer political and economic ties, with Mr Barroso saying a free-trade area with Ukraine was the first aim.
The two parties signed an agreement that should make it easier to issue short-stay visas to Ukrainian citizens travelling to the EU.
Another agreement was signed establishing procedures for repatriating illegal immigrants to Ukraine.
President Yushchenko gave EU leaders renewed assurances over security of energy supplies.
Mr Barroso welcomed the agreement reached earlier this week between Russia and Ukraine on the prices of natural gas.
"We don't anticipate any problems, at least for this year," he said.
Much of Europe's gas comes from Russia and is piped across Ukraine.
In January gas supplies to Ukraine were briefly cut off in a price dispute - a move which affected a number of European countries.