Argentina didn't see that coming: TangObama

State dinners can be staid. But not on Wednesday, when US President Barack Obama, on a visit to Argentina, was game for a go at tango -- with a pro, no less.

Looking relaxed practicing a few steps with dancer Mora Godoy, while his wife First Lady Michelle Obama gave it a whirl with dancer Jose Lugones, the Obamas held their own on tango's home turf.

The US president "was telling me he didn't know how to dance (tango)", Godoy said. "I told him 'just follow me'."

"He said 'OK', and then he started to dance. Then I started following his lead because he is a very good dancer," Godoy told the La Nacion daily.

Before the dinner with President Mauricio Macri at the Kirchner Cultural Center, Obama made remarks and quoted the late Argentine novelist Jorge Luis Borges's defense of "the inviolable right to have hope".