Helsingborg, May 22 -- Asserting Washington's firm stance on global maritime security, US Secretary of State Marco Rubio has redoubled pressure on Tehran, identifying its aggressive manoeuvres in vital trade corridors as a non-negotiable hurdle in ongoing diplomatic discussions.

Rubio, who is in Helsingborg, Sweden, highlighted that ensuring unhindered freedom of navigation remains a primary objective for the international community.

Rubio said another major issue to be addressed in negotiations is Iran's position on the Strait of Hormuz.

The top American diplomat exposed Tehran's efforts to institutionalise its maritime restrictions by seeking regional partnerships to legitimise commercial shipping levies.

He said Iran is "trying to ...