Barack Obama's daughters have met Pope Francis, but the United States president was unable to arrange for similar with Lionel Messi.

President Obama is in Argentina for the first time, strengthening ties with one of South America's largest economies.

Giving a speech in Buenos Aires, he revealed his daughters Sasha and Malia had met Pope Francis – yet Barcelona and Argentina superstar Messi was far tougher to get a hold of.

"I also wanted to bring my daughters here, so they could see the beauty and the vibrancy of this city," he said, via Marca.

"They've already met one famous Argentinean - His Holiness Pope Francis. Now they want to meet Messi, but I could not arrange that."

Messi is with the national team as Argentina prepare for World Cup qualifiers against Chile and Bolivia.