By Joshua McElwee and Leila Miller

BUENOS AIRES, Nov 8 (Reuters) - Pope Leo arrived in Argentina from Uruguay on Sunday for the second leg of a 12-day tour across South America, ahead of a closely watched speech to Argentine President Javier Milei, a libertarian seen as a close ally of US ‌President Donald Trump.

The address by the first US-born pope may underscore tensions between the Vatican and Milei, whose austerity agenda has been criticized by the Church ‌for hitting the poorest hardest. The Argentine leader has also strongly supported the Iran war, which Leo has denounced to Trump's ire.

Leo was greeted at Buenos Aires' Jorge Newbery airport under clear skies by Milei and ​a military band lining a red carpet as the pope descended from the plane. The president and pope shared a long, amicable handshake in a warm first public interaction.

Leo also greeted Karina Milei, the pre...