U.S. National Security Adviser John Bolton, speaking after the United States increased sanctions against Iranian officials, said Washington was still willing to talk to Iran.
"The president has held the door open to real negotiations to completely and verifiably eliminate Iran's nuclear weapons programme, its ballistic missile delivery systems, its support for international terrorism and other malign behaviour worldwide," Bolton said in Jerusalem. "All that Iran needs to do is to walk through that open door."
The United States backed out of the 2015 international agreement curbing Iran's nuclear programme in May last year. Iran denies it is trying to build nuclear weapons.
U.S. President Donald Trump on Monday targeted Iranian Supreme Leader Ayatollah Ali Khamenei and other Iranian officials with sanctions, inreasing pressure on Iran afterIranian forces shot down an unmanned American drone.
Iran's ambassador to the United Nations, Majid Takht Ravanchi, told reporters on Monday that Iran would not agree to talks with the United States while it is under the threat of sanctions.
Meanwhile, Iran said that US sanctions on its leaders represent the "permanent closure" of diplomacy with Washington,
"Imposing fruitless sanctions against Iran's supreme leader and the commander of Iran's diplomacy is the permanent closure of the path to diplomacy with Trump's desperate government," ministry spokesman Abbas Mousavi said in a tweet.