President Donald Trump said his national security adviser John Bolton would leave the US administration, removing a hard-line architect of the ongoing pressure campaign against Iran.

Trump, who tweeted that he “disagreed strongly” with many of Bolton’s policy suggestions, reportedly clashed with the veteran of the four presidential administrations over the withdrawal of American forces from Afghanistan and Syria.

It appears the left-over National Security Council staff will remain in place for now, with Bolton ally Charles Kupperman taking over in an interim capacity. Where will Bolton’s departure cause changes?

Iran ‘maximum pressure’ campaign: Just weeks ahead of the UN General Assembly, Bolton’s exit raised speculation that the United States could reenter negotiations with Iran for a fresh nuclear deal. “Sure,” Secretary of State Mike Pompeo told reporters on Tuesday, when he was asked if Trump was willing to engage without preconditions on the sidelines of the world body’s annual meeting. For now, Secretary of the Treasury Steven Mnuchin said the United States would keep up its campaign of sanctions and military pressure.