Washington, June 2 -- US Secretary of State Marco Rubio has mounted a firm defence of Washington's military approach toward Tehran, asserting that Iran had sought to develop its conventional arms infrastructure as a "shield" to safeguard its nuclear ambitions.

Testifying before the US Senate Foreign Relations Committee on Tuesday, Rubio stated that recent American military operations had drastically diminished Iran's military capabilities, effectively stripping its conventional forces of any credible deterrent power.

"What they tried to do is they were going to try to build a conventional shield and hide behind that conventional shield," Rubio told lawmakers.

The top American diplomat emphasised that Tehran's maritime forces had suffer...