The initiative was formed in 1989 to strengthen ties between the 18 central and southeast European member countries and the EU.
Kosovo was a key issue on the agenda, but was not invited to the meeting.
The leaders of the former Serbian province criticised the decision and insisted that an independent Kosovo is a reality that must be recognised.
However, Crvenkovski said such an invitation would have required a consensus from all 18 members of the CEI, and that was not possible since Serbia refused to recognise Kosovo's declaration of independence on February 17.
The EU signed a pre-membership trade-and-aid pact with Serbia this week in an attempt to boost pro-Western parties before elections in Serbia on May 11.
Macedonia, with its own large and restive Albanian minority, wants to establish good relations with Kosovo, but has not yet recognised it because of a border dispute.
Bamir Topi, the Albanian president, told the summit that Kosovo should receive a clear signal that it will eventually become part of the EU and Nato expansion process.
"That would guarantee that the political emancipation of the western Balkans has entered an irreversible path," he said.
A draft summit joint statement says that EU and Nato integration should not be considered completed without inclusion of all western Balkan states.
"However, the region is still not irreversibly on the road to Europe," the draft document said.
The CEI members include Albania, Austria, Belarus, Bosnia-Herzegovina, Bulgaria, Croatia, the Czech Republic, Hungary, Italy, Macedonia, Moldova,Montenegro, Poland, Romania, Serbia, Slovakia, Slovenia and Ukraine.
Ten are EU members, three have EU candidate status and five have not joined the bloc.
Turkey, which is not a member of the CEI or the EU, also attended the summit.
The last CEI meeting was held 2007 in Brno, in the Czech Republic.