She added that this was a message to the US officials she had met or would meet during her five-day visit to Washington when she would try to win US support for Croatia's admission to the military alliance as soon as possible.
Croatian officials had said earlier that Croatia hoped to receive an invitation for NATO membership no later than 2008 and that expected signals to that effect at a NATO summit in Riga in November this year.
"I will not speculate about dates because I do not wish to raise the level of expectation in Croatia," Grabar-Kitarovic said.
The minister said that she expected the efforts of Croatia, Macedonia and Albania, members of the US-Adriatic Charter, to join NATO to be recognised at the Riga summit and that "the message that NATO membership remains open will be reaffirmed".
She said she believed the NATO officials when they said that membership of the North Atlantic Treaty Organisation was based on the individual achievements of each country.
Grabar-Kitarovic thanked Visclosky, the chairman of the Croatian congressional caucus, for support in two recent resolutions in which the House of Representatives and the Senate recommended admitting Croatia to NATO as soon as possible.
She said that the support of the US Congress and administration was very important to Croatia in its ambitions to become a member of NATO, and expressed hope that it would continue.
Visclosky, who played an important role in the adoption of the two congressional resolutions, said that there was no reason to doubt that further support to Croatia's aspirations would dissipate in the House and the Senate.
Also on Wednesday, Grabar-Kitarovic received a presidential medal from the George Washington University where she had done predoctoral research in international relations and security issues as a Fulbright scholar in 2002/03.
Presenting her the medal, University President Stephen Joel Trachtenberg said that the medal was a mark of recognition of Grabar-Kitarovic's efforts in Croatian foreign policy that helped Croatia become the most successful country in the Balkans.
Established in 1998, the presidential medal is the highest honour awarded by the President of the University. Among the politicians who have received it are Vaclav Havel, Mikhail Gorbachev and Abba Eban.