Erdmann said the decision on inviting a state to join was not tied to dates or NATO summits but was made solely on the basis of each state's individual achievements.
He added Croatia had made great progress and now needed to have an exhaustive discussion on whether the Croatian people wanted to be part of NATO as an institution of the Euro-Atlantic family.
Erdmann said the issue of a broad consensus on that must still be settled among political parties but also with the public.
He visited Zagreb as part of annual consultations on the implementation of the partnership's goal.
According to a statement from Mesic's office, Erdmann reiterated the position on the frequently asked question of whether Croatia would have to send troops to Iraq once it joined NATO.
He said that like the alliance's current 26 members Croatia would decide by itself in which operations to participate and in what scope.
President Mesic underlined the consensus in Croatia on accession to the European Union and NATO. He said other countries in the region should follow Croatia's path and that Croatia was ready to help them in that.