"Looking ahead, there are plenty of challenges, in particular in terms of security," Erjavec told reporters ahead of the 5-6 September event.

The debates, delving into specific challenges, will revolve around major developments over the past year, including migrations, terrorism and the British decision to leave the EU.

"I believe we've picked the right topics," Erjavec stressed.

Many senior officials will be in attendance, with Erjavec highlighting Croatian President Kolinda Grabar Kitarović and Albanian Prime Minister Edi Rama.

Secretary General of the Organization for Security and Co-operation in Europe (OSCE) Lamberto Zannier and Director General of the United Nations Office at Geneva Michael Moller will be among the over 700 guests.

Virtually all foreign ministers from the region will come to Bled, with only the participation of Croatia's foreign policy chief Miro Kovač yet to be confirmed.

Turkish Foreign Minister Mevlüt Cavusoglu has been announced as a guest but his attendance depends on Turkey's domestic situation, said Erjavec.

Erjavec said he would hold bilateral meetings with all foreign ministers, as well as members of the US administration and representatives of international organisations.

The debates would focus on issues such as migrations, terrorism and Brexit, in particular on "how to react if the migration wave occurs again."

"It would therefore be interesting if the Turkish minister could attend," according to Erjavec, as Turkey is the key country in the region.