President Donald Trump is expected to announce on Tuesday his decision on whether he will continue or withdraw US involvement in the Iran nuclear deal ahead of the Saturday deadline.
Pulling out of the deal would mean renewing sanctions on Iran that were lifted when the deal was signed in 2015.
Meanwhile, Iranian President Hassan Rouhani is expected to speak at an oil and gas exhibition in Tehran.
Being one of the largest oil producers in the world has helped Iran survive decades of economic isolation, and it is something Iran's leaders hope they can do again.
Al Jazeera's Zein Basravi reports from Tehran.
