US President Donald Trump has said he is not seeking war with Iran, as he dispatched two top officials to the Middle East amid heightened tensions.
"I'm not looking for war," Trump said on Sunday on NBC's Meet the Press programme.
The downing of a US surveillance drone on Thursday by Iran's elite Islamic Revolutionary Guard Corps (IRGC) had brought the two foes to the brink of war. Tehran said the drone violated its airspace but Washington insisted it was flying over international waters in the Gulf.
Trump had earlier said that he called off a military attack to retaliate for the downing of the unmanned aircraft out of concern it would have been a disproportionate response.
Trump has indicated that he would also be prepared to seek a deal to bolster Iran's flagging economy, an apparent move to defuse tensions.
"I think they want to negotiate. And I think they want to make a deal. And my deal is nuclear. Look, they're not going to have a nuclear weapon," Trump said.
Last year, Trump withdrew the United States from a 2015 accord between Iran and world powers that curbed Tehran's nuclear programme in exchange for easing sanctions. Relations in the region have worsened significantly since then.
'Negotiate with no preconditions'
US Secretary of State Mike Pompeo, who is on his way to Saudi Arabia and the United Arab Emirates (UAE), reiterated on Sunday that Washington wanted talks with Tehran.
"We're prepared to negotiate with no preconditions," he said. "They know precisely how to find us. I am confident that at the very moment they're ready to truly engage with us we'll be able to begin these conversations. I'm looking forward to that day."
If a conflict breaks out in the region, no country would be able to manage its scope and timing.
Iran's Major General Gholamali Rashid
Pompeo also said "significant" sanctions on Iran would be announced on Monday aimed at further choking off resources that Tehran uses to fund its activities in the region.
"We are going to deny them the resources they need to do that, thereby keeping American interests and American people safe all around the world," Pompeo said before leaving for the Middle East.
Iran played down the impact of any new US sanctions. They were "just propaganda, as all sanctions ... have been imposed and there are no more sanctions left", state-run news agency IRIB quoted Foreign Ministry spokesman Abbas Mousavi as saying.
Iran denies seeking nuclear weapons and refers to a fatwa or religious decree issued in the early 2000s by Iran's top authority Ayatollah Ali Khamenei that bans the development or use of nuclear weapons.
But a hawk in Trump administration, National Security Advisor John Bolton, sought to maintain military pressure on Iran.
"Neither Iran nor any other hostile actor should mistake US prudence and discretion for weakness. No one has granted them a hunting license in the Middle East," Bolton said during a visit to Israel.
Iran has said it would respond firmly to any threat and warned on Sunday of the risks of a military confrontation.
"If a conflict breaks out in the region, no country would be able to manage its scope and timing," Major General Gholamali Rashid said, according to the semiofficial Fars news agency.
"The American government must act responsibly to protect the lives of American troops by avoiding misconduct in the region."
Iranian President Hassan Rouhani accused the Americans of stoking tensions through what Iran has called the violation of its airspace by the US military drone, Fars reported.
Diplomatic efforts are under way to ease tensions following attacks on oil tankers in the Gulf in recent weeks that the US blames on Iran and the shooting down of the drone last week. Tehran has denied involvement in the tanker attacks, which no one has claimed responsibility for.
Andrew Murrison, Britain's minister for the Middle East and North Africa, said on Sunday that he had "open, frank and constructive" talks with Iranian government representatives in Tehran.
"I reiterated the UK's assessment that Iran almost certainly bears responsibility for recent attacks on tankers in the Gulf of Oman," Murrison said and called for such activity to stop.
The United Kingdom, France, Germany and the European Union are signatories to the 2015 deal and Tehran wants the Europeans to shield Iran from the Trump administration's sanctions through a trade mechanism.
After the talks with Murrison, Iran said it would not back down from its decision in May to reduce some of its commitments under the pact, state TV quoted Iran's Deputy Foreign Minister Abbas Araqchi as saying.
"The European signatories of the deal lack the will to save the deal. Our decision to decrease our commitment to the deal is a national decision and it is irreversible as long as our demands are not met," Araqchi said.
Another source of regional tension is the more than four-year-old Saudi-UAE-led war in Yemen that has pushed millions towards the brink of famine.
In recent weeks, the Houthis who have been fighting the Saudi-led coalition, have stepped up attacks on Saudi border regions. In the latest assault, one person was killed and seven others wounded in an attack on Abha airport close to the Yemen border.
The Saudi-UAE coalition intervened in Yemen in 2015 to try to restore the internationally recognised President Abd-Rabbu Mansour Hadi who was overthrown by the Iran-aligned Houthis in late 2014.