The Holy Father made that disclosure when he met with thousands of pilgrims in the courtyard of the papal residence of Castel Gandolfo to pray the midday Angelus.
He appealed to Catholics worldwide to pray for the success of his Sept. 22-27 trip to the two Asian nations.
The 95th international apostolic trip of this pontificate will take John Paul II to Kazakhstan, whose population, he noted, "includes more than 100 different ethnic groups and cultures."
The Holy Father will have a chance to practice his Russian, the common language of the country. He studied the language during World War II.
Unlike his recent pastoral visit to Ukraine, the Pope will be welcomed both by Muslims and Orthodox. Ninety percent of the people who requested tickets for the Pope´s public Mass in Astana, the capital, are Muslim, according to the Fides agency.
Armenia, the Holy Father said, "is homeland to one of the most ancient peoples of the Near East, who embraced Christianity officially some 17 centuries ago, and is the depository of a religious and cultural heritage of singular richness."
John Paul II had hoped to visit that nation in 1999 to see Armenian Apostolic Patriarch Karekin I, a great supporter of dialogue between Christians. But after the patriarch had taken ill and went to his deathbed, the papal visit was canceled.
In the city of Etchmiadzin, symbol of persecuted Christianity in Armenia, John Paul II will try to promote ecumenical dialogue.
The latter is possible thanks to the resolution of a theological issue on the nature of Christ, which separated the two Churches for 1,500 years. The resolution was confirmed in a joint declaration signed by the Pope and the leader of the Armenian Apostolic Church in 1996.