Iran's Foreign Minister Mohammad Javad Zarif dismissed talks with Washington in a tweet late Tuesday, saying "threats, sanctions and PR stunts won't work".

Responding to US President Donald Trump's surprise offer of talks without preconditions, Zarif wrote: "Iran & US had 2 yrs of talks.

"With EU/E3+Russia+China, we produced a unique multilateral accord -- the JCPOA (nuclear deal). It's been working. US can only blame itself for pulling out & leaving the table."

Trump said Monday he was open to talks with Iran's leaders "any time" and reiterated the point the following day, telling reporters: "I have a feeling they'll be talking to us pretty soon."

But with the US pulling out of the 2015 nuclear deal in May and set to reimpose full sanctions from August 6, most of Iran's officials are unimpressed by the offer.

"Threats, sanctions & PR stunts won't work," Zarif wrote on Twitter.

"Try respect: for Iranians & for (international) commitments."