The US State Department praised the European Union's commitment to keep the door "open" for the Western Balkan countries.
"We welcome the EU statement on the Western Balkans," Ned Price, a spokeswoman for the institution, said in a Twitter post.
"Albania, Bosnia and Herzegovina, Kosovo, Montenegro, North Macedonia and Serbia continue to demonstrate their commitment to reform. "It is important that the door to the EU is kept open for them."
The European Union held a summit in Slovenia on Wednesday with representatives of six Western Balkan countries aiming for EU membership.
The EU adopted a statement saying it supported the European perspective of the Western Balkan states and "reaffirmed its commitment to the enlargement process" of the European bloc.
But, according to the statement, the enlargement process will be based on "credible reforms by partners, fair and rigorous conditioning and the principles of individual merit".
Of the Western Balkan countries, Montenegro and Serbia have made the most progress on the path to European integration.
These two countries have opened several chapters of membership negotiations.
North Macedonia and Albania are still awaiting for the start of these negotiations, while Kosovo and Bosnia and Herzegovina have only a Stabilization and Association Agreement with the EU - which is the first step towards bloc membership.