The United States will not lift sanctions on Iran in order to negotiate, US President Donald Trump tweeted late on Saturday, seemingly in response to a Der Spiegel interview with Iran’s foreign minister.

Iran’s Foreign Minister Mohammad Javad Zarif responded on Sunday by tweeting an excerpt from the interview with Der Spiegel published on Friday, where he said Iran is still open to negotiations with America if sanctions are lifted.

Tensions between Iran and the United States have reached the highest levels in decades after the US killed top Iranian General Qassem Soleimani in a drone strike in Baghdad on January 3, prompting Iran to fire missiles days later at bases in Iraq where US troops are stationed.