Iran threatened on Saturday to block a corridor planned in the Caucasus under a regional deal sponsored by U.S. President Donald Trump, Iranian media reported, raising a new question mark over a peace plan hailed as a strategically important shift.

The leaders of Armenia and Azerbaijan shook hands as they joined President Donald Trump at the White House on Friday for a peace summit where they signed an agreement aimed at ending decades of conflict.

Language in the "peace deal" will give the U.S. exclusive rights to develop a key transit route that will be named after Trump.