Iran will shift to a "fully offensive" military ​posture because efforts to negotiate a permanent end to the war with the U.S. have stalled, a senior Iranian official said on Monday, as Washington ruled out extending ‌a temporary ceasefire agreement, Reuters reported. 

Outward progress towards peace talks and a resumption of oil tanker traffic through the strategic Strait of Hormuz has ground to a halt, threatening to extend the conflict that the U.S. and Israel launched with attacks on Iran on February 28.