"Despite limited resources, the countries of Southeast Europe have actively supported the international coalition against terrorism," the report said.
Croatia was not mentioned separately, but in a section dealing with anti-terrorism efforts in the region.
The State Department said that Albania, Bosnia and Herzegovina, Bulgaria, Croatia, Greece, Hungary, Macedonia, Moldova, Romania, Serbia and Montenegro, Slovenia and Turkey cooperated through the Southeast Europe Cooperation Initiative (SECI).
Acting through the SECI Regional Centre to Combat Transborder Crime, based in Romania, the 12 countries cooperated to combat organised crime and various forms of trafficking, enhance border security and improve training for border security personnel.
The report said that Bosnia-Herzegovina had taken decisive action in apprehending suspects and shutting down non-governmental organisations and bank accounts tied to terrorist-linked organisations.
In 2004, Bosnian Federation authorities disrupted the operations of al-Furqan, al-Haramain, al-Masjed al-Aqsa and Taibah International, organisations listed by the United Nations as having direct links with al-Qaida.
The US State Department said it remained concerned about the foreign Islamic extremists who stayed in Bosnia after the 1992-1995 war.