U.S. President Donald Trump's administration has repeatedly told mediators that it has no interest in returning to the terms of the memorandum of understanding reached with Iran in June, complicating the frantic diplomatic efforts that took place this week, according to sources involved in the details who spoke to The Wall Street Journal. Trump has fixated on a policy of economic pressure on Iran and is willing to wait to see if the strategy bears fruit, the sources said. According to them, the president in particular is no longer interested in the memorandum of understanding, which came under harsh criticism in the U.S. for being too soft on Iran.