Iran on Tuesday warned that new US sanctions targeting its access to surveillance technology were "negative" and could adversely affect its crucial talks next month with world powers over Tehran's nuclear programme.

"We consider any kind of sanction as negative and a wrong step," foreign ministry spokesman Ramin Mehmanparast said in his weekly briefing.

"Any decision by Western officials, including the Americans, can affect the atmosphere of talks," he said.

Mehmanparast was reacting to measures announced by US President Barack Obama on Monday aimed at preventing Iran, and its chief ally Syria, from acquiring surveillance software and monitoring equipment to control its population.

The extra sanction targets companies that help Tehran create systems to track or monitor people to help violent repression.

Obama's executive order was announced ahead of May 23 talks to be held in Baghdad between Iran and the so-called P5+1 group comprising the United States, Russia, China, France, Britain and Germany.

Iran and the P5+1 met in Istanbul on April 14 to revive talks that had been stalled for 15 months, and agreed to hold the more substantive round of negotiations in the Iraqi capital.

The new US measures add to a series of unilateral Western sanctions against Tehran over its nuclear activities.

The UN Security Council has also imposed four rounds of multilateral sanctions.

Iran denies Western allegations its nuclear programme has a military component to develop atomic weapons. It has made the lifting of the sanctions a key demand in the nuclear talks.

"We believe the lifting of illegal sanctions (against Iran) could be a positive step in the right direction for the continuation of cooperation in the next round talks with the P5+1 group," Mehmanparast said.

He said Iran was going into the talks with a "positive outlook".