DUBAI (Reuters) - Iranian lawmakers chanted “Death to America” during a parliament session on Sunday after a speaker accused the United States of being the “real world terrorist”, amid escalating tension with Washington following the downing of an unmanned U.S. drone.

U.S. President Donald Trump said on Friday he aborted a military strike to retaliate for the drone incident because it could have killed 150 people, and signaled he was open to talks with Tehran.

Iran said on Saturday it would respond firmly to any threat against it.

“America is the real terrorist in the world by spreading chaos in countries, giving advanced weapons to terrorist groups, causing insecurity, and still it says ‘Come, let’s negotiate’,” the parliament’s deputy speaker, Masoud Pezeshkian, said at the start of a session broadcast live on state radio.

“Death to America,” chanted many lawmakers.

The chants, often repeated since the 1979 Islamic revolution which toppled the U.S.-backed Shah, came weeks after Trump said in a U.S. television interview: “They (Iranians) haven’t screamed ‘death to America’ lately.”