Romania and Bulgaria won praise from the head of the European Commission's enlargement department for upgrading their justice systems.
"Both of them under EU pressure have made enormous progress," Michael Leigh said in an interview in Brussels, as cited by Bloomberg agency. "We must give full credit where credit is due.''
Leigh would not specify whether the European commission would propose that the two ex-communist nations join on time, saying "there are still a number of challenges to be met."
The commission, the EU's executive arm, will recommend May 16 whether to delay the accession of Romania and Bulgaria - or one of them - until January 2008. The final decision rests with the EU's national governments.
Romania and Bulgaria, with a combined population of 30 million, are counting on entry to help raise per-capita wealth from a third of the EU average. Their accession would expand the world's largest trading bloc to 27 nations and to the Black Sea.