US Secretary of State Marco Rubio has said that reaching a peace agreement with Iran is “extremely difficult” and that Washington will keep up economic pressure until Tehran stops targeting commercial shipping in the Strait of Hormuz. Rubio made the remarks in an interview with CNBC-TV18 / Network18 in Mumbai on Tuesday, during his three-day visit to India, Al Jazeera and The Hindu BusinessLine reported.

“It’s tough to make a deal with the Iranian regime,” Rubio said, according to reports of the interview. Accusing Iran of openly targeting merchant vessels, he said: “You haven’t seen that since the Second World War. They are doing Nazi U-boat tactics.” Rubio said US forces were intercepting most Iranian drones and missiles launched at ships, although some were still getting through — that is his account of the interceptions, not an independently verified tally. He also said Indian sailors had been among those affected by the attacks on shipping, The Hindu BusinessLine reported.

On traffic through the strait, Rubio put maritime and energy flows at roughly 80 to 100 percent of pre-war levels, Al Jazeera reported. Iran has repeatedly denied that figure. Iranian officials have previously acknowledged stepping up attacks on vessels they say violate Tehran’s restrictions in and around the strait, while the US has maintained naval operations to protect commercial shipping.

Rubio also defended President Donald Trump’s decision to use a national security waiver on legislation proposing tougher tariffs and sanctions linked to Russia, saying sanctions fall not only on Russia but on anyone who does business with it and must be balanced against the consequences for other countries, The Hindu BusinessLine reported. Asked about Pakistan, he reiterated that the US opposes terrorism anywhere, but said Washington “has to have a relationship” with Islamabad, citing its nuclear weapons and geographic importance.

The Strait of Hormuz is one of the world’s most important oil routes, linking Gulf producers to markets in Asia, including India, and its safety matters directly to the lakhs of Indian and Punjabi workers and sailors employed across the Gulf. Rubio’s remarks underline how far apart Washington and Tehran remain even as mediation efforts continue.