Albania and Croatia formally joined NATO on Wednesday, bringing the total number of member states of the alliance to 28.

"Today, Albania and Croatia have completed the accession process, and have joined the alliance as members," said NATO Secretary General Jaap de Hoop Scheffer in a statement.

"I warmly congratulate them on this historic achievement. In becoming NATO members, Albania and Croatia share the benefits and responsibilities of collective security."

Croatia was able to join NATO ahead of the April 3-4 NATO summit in Strasbourg, France, and Kehl, Germany, after Slovenia deposited with Washington its instrument of ratification for Croatia at the last minute.

Slovenia's ratification was deposited on Monday after a referendum to repeal the country's parliamentary approval failed to materialize. The two former Yugoslav republics have a border dispute.

Albanian and Croatian ambassadors in Washington deposited their countries' documents of accession with the Department of State, completing the full accession process.

The heads of state and government of the two countries will be formally welcomed at the NATO summit. Starting from Thursday, Albania and Croatia will participate in NATO committee meetings as full members of the alliance, said NATO spokesman James Appathurai.

A flag-raising ceremony marking the accession of Albania and Croatia will be held at NATO headquarters in Brussels on April 7.

The two countries have worked hard to meet NATO standards with regard to democracy and with regard to the state of their militaries, said Appathurai.

They have overcome a difficult time in Balkan history to become contributors to regional security and to international security through NATO already, he said.

"Now they will take their full place in this alliance. They will have their full voice, equal to all other allies as NATO takes its decisions. They will benefit from the collective security the alliance offers, but they will also bear the responsibilities that collective security requires between allies."

The two Western Balkan countries were invited to join the military alliance at the previous NATO summit in Bucharest, Romania, a year ago.

(Xinhua News Agency April 2, 2009)