With our entry to NATO, we have also ensured the security for our country, Mesic said in a statement.
"However, NATO is not only a military alliance but also an alliance which protects democratic values, and our entry into that alliance confirms that Croatia has embraced and defends high democratic standards," the Croatian head of state said.
"With its entry into NATO, Croatia is entering a circle of developed economies with which it can develop economic relations more intensively than before to the benefit of our economy," Mesic said.
He congratulated Albania which together with Croatia became a NATO member at a ceremony in Washington earlier today.
By depositing the ratification documents on their NATO admission in the US State Department, Croatia and Albanian became full members of the alliance.
The ratification documents on the two countries' NATO accession were submitted Croatia's Ambassador to the USA, Kolinda Grabar Kitarovic, and Albania's Ambassador, Alexander Sallabanda.
Croatia's Parliament ratified the document on 25 March and sent it to Washington given that the United States is the depositary of the North Atlantic Treaty.