NEW YORK (CBSNewYork)Pope Francis is worried about making a good impression when he visits the United States for the first time in September, a Vatican expert said.

John L. Allen Jr., a veteran Vatican watcher and author of the book “The Francis Miracle,” told WCBS 880’s Rich Lamb the pope has been making calls to his Jesuit contacts to learn more about the church in the United States and is self-conscious about his English.

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But Allen said the pontiff should have nothing to fear.

When he went to South Korea and also when he was in Sri Lanka and the Philippines, he gave all his public speeches in English, and they were fine,” Allen said. “They were perfectly comprehensible.

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“He really does not need to worry because whatever his struggles in English are, they have not prevented him from having a 90 percent approval rating in this country. I think he’s going to be OK.”

Francis will visit Washington, New York and Philadelphia during the Sept. 22-27 trip. While in New York on Sept. 24-26, he is scheduled to address the United Nations General Assembly and might visit the World Trade Center site, St. Patrick’s Cathedral and celebrate Mass at Madison Square Garden.

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He will also address Congress in Washington and appear at the World Meeting of Families in Philadelphia.