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.

Russia cautiously welcomed a US-brokered draft deal between Armenia and Azerbaijan on Saturday, but Moscow's regional ally Iran rejected the idea of a new border corridor backed by President Donald Trump.

Iran vehemently opposes the US-brokered peace agreement between Armenia and Azerbaijan, specifically the creation of the 'Trump Route' transit corridor. Tehran views the corridor as a threat to regional stability,