Twenty-nine foreign ministers and a number of deputy ministers and state secretaries have announced their participation, the head of the commission preparing the event, Ambassador Fuad Sabeta, told the media.

The Croatian delegation will be led by Foreign Affairs and European Integration Minister Gordan Jandrokovic.

The main objective of the meeting is to reassert EU support for the European prospect of Southeast European countries within the Treaty of Lisbon.

The meeting, organised by Spain, is taking place 10 years after a Zagreb summit which pointed to the structural, political and economic reforms the countries in the region have to carry out on their road to the EU.

A declaration is expected to be adopted at the end of the event. Bosnian Foreign Minister Sven Alkalaj told press today the declaration would be written by representatives of EU countries.

Regarding its content, he said it would likely focus "on visa liberalisation (for Bosnia-Herzegovina and Albania), the security and stability issue in the region and the settlement of outstanding issues before EU membership".

British Foreign Secretary William Hague has confirmed his attendance, as have the foreign ministers of Italy and Spain, Franco Frattini and Miguel Angel Moratinos respectively.

The foreign ministers of Germany and France will not attend. Announcements of the meeting were followed by speculation that influential countries such as Germany do not want to give any explicit promises about the future EU membership of Southeast European countries.

The US will attend the meeting as an observer represented by Deputy Secretary of State James Steinberg.

According to available information, Russia's attendance will be merely symbolic. The country will be represented by its ambassador to Bosnia-Herzegovina.

The participants in the event will be presented by name and not title or state, a compromise solution reached to ensure the attendance of Serbia and Kosovo.

Catherine Ashton, High Representative for Foreign Affairs and Security Policy/Vice-President of the European Commission, and Commissioner for Enlargement Stefan Fuele will also participate in the June 2 High Level Meeting in Sarajevo.

The main objective of the meeting - where EU Foreign Ministers and Foreign Ministers from Western Balkans countries will also participate - is to reaffirm the EU's commitment to Western Balkans and its European perspective.

Ashton said ahead of the meeting that "integrating the Western Balkans into the European family of nations remains one of the last challenges to building a democratic and unified Europe".

"In Sarajevo, the EU will reaffirm the Balkans' place in Europe and the European perspective for the region", she said in a statement published by the European Commission.

Fuele was quoted as saying that the event "provided a timely confirmation of the perspective of EU membership for the Western Balkans and the continuation of the enlargement process".