The UK Foreign Secretary William Hague rejected a claim the government was "softening" its approach to Iran.
Speaking in the parliament, Mr Hague described the UK as "absolutely relentless" in its efforts to defeat terrorism around the world and added: "I can assure you that there is no softening of any of our policies in relation to Iran.
More top news
Ministers say the Great Repeal Bill will avoid a "black hole" in the UK's law when we leave the EU. Details are to be published on Thursday.
The triggering of Article 50 has dominated newspaper headlines on Thursday, with many focusing on a possible threat over security by Ms May.
Twelve people have been killed and three injured after a pick-up truck and a church minibus crashed head-on in Texas.