Politicians held the impromptu demonstration the day after Mr Trump’s decision.
As well as the paper flag, they also burned a piece of paper representing the nuclear deal.
The chant “Death to America” long has been used in Iran since its 1979 Islamic Revolution. It also has been common to hear it within parliament.
However, Wednesday’s demonstration reflected public anger in Iran after Mr Trump’s decision.
Iran’s 2015 nuclear deal imposed restrictions on its nuclear programme in return for the lifting of most US and international sanctions.
However, the deal came with time limits and did not address Iran’s ballistic missile programme or its regional policies in Syria and elsewhere.
Mr Trump has repeatedly pointed to those omissions in referring to the accord as the “worst deal ever”.
Proponents of the deal have said those time limits were meant to encourage more discussion with Iran in the future that could eventually address other concerns.
Many Iranians are worried about what Mr Trump’s decision could mean for their country.
The Iranian rial is already trading on the black market at 66,000 to the dollar, despite a government-set rate of 42,000 rials. Many say they have not seen any benefits from the nuclear deal.
Iran’s poor economy and unemployment sparked nationwide protests in December and January that saw at least 25 people killed and, reportedly, nearly 5,000 arrested.