Vatican City, Sep 19 (IANS/AKI): Pope Francis spent the summer "diligently" studying English ahead of his five-day visit to the US, the Vatican secretariat of its third in command, Monsignor Angelo Becciu said.

"He spent the summer preparing for this trip and was constant and diligent in taking English lessons," Becciu said on Friday.

"I think he will do well, because he has already prepared scrupulously where he has to speak and read.

"He is a good student who is at pains to do things well. He went through each of his addresses several times, preparing, correcting and discussing them," said Becciu.

"He wants to get across the Evangelical message in the best way possible."

US President Barack Obama and First Lady Michelle Obama will greet Francis when he arrives in Washington on September 22 at Andrews air force base.

The pope's US visit will also include stops in New York and Philadelphia, where all 10,000 tickets to an open air mass are already taken.

Francis will address the UN in New York on September 25, where he is expected to focus on the need for peace in a conflict-torn world facing the biggest refugee crisis since World War II, the Vatican said.