Pope Francis has issued telegrams to the heads of State of the countries through whose airspace his flight has passed on the way to Ireland.

The greetings, signed Franciscus PP., have been sent to the Italian President Sergio Mattarella, the President of the Swiss Federation Alain Berset, French President Emmanuel Macron, and to Queen Elizabeth.

In his message to the Italian President, Pope Francis said he invoked on the Italian nation "abundant gifts of foresight and wisdom to continue to appreciate and tend to the value of marriage and the family."

To the Swiss President, Pope Francis telegramed: "I extend cordial greetings to your excellency and the people of Switzerland as I fly over your country on my way to Ireland invoking the blessing of Almighty God upon the nation, I pray that He may grant you peace and well-being."

In a telegram to President Macron, Pope Francis said: "I offer best wishes and the assurance of my prayers as my journey to Ireland takes me over France. I willingly invoke upon you and your fellow citizens the blessings of joy and peace."

Pope Francis also extended "cordial greetings" to Her Majesty Queen Elizabeth, "the members of the Royal Family, and the people of the United Kingdom as I fly over your British airspace on my way to Ireland. I willingly invoke upon all of you they abundant blessings of Almighty God."

Pope Francis with RTÉ's Europe Editor Tony Connelly on the flight