A European Union initiative to establish closer relations with six ex-Soviet states was overshadowed on Thursday by the absence of many leaders from the summit that launched the project.

Nicolas Sarkozy, France’s president, Silvio Berlusconi, Italy’s prime minister, José Luis Rodríguez Zapatero, Spain’s premier, and Gordon Brown, the UK prime minister, each stayed away from the Prague summit, as did Alexander Lukashenko and Vladimir Voronin, presidents of Belarus and Moldova respectively.