Iran’s nuclear programme and control of the Strait of Hormuz remain major sticking points, despite mediation efforts by Qatar and Pakistan. HELSINGBORG: The United States has seen some progress towards a deal with Iran but more work is required, US Secretary of State Marco Rubio said on Friday (May 22), while Iran 's foreign ministry spokesman said the two sides' differences were deep and significant. Intensifying diplomacy to end the conflict, Pakistan's military chief arrived in Tehran on