Donald Trump authorized the killing of Soleimani seven months ago

The report also indicated that the presidential directive was issued in June, on the condition that he would sign off on any specific operation to kill Soleimani.

Donald Trump authorized the killing of Soleimani seven months ago
US President Donald Trump authorized the killing of IRGC chief Qasem Soleimani seven months ago, according to a report released by NBC news.
The report also indicated that the presidential directive was issued in June, on the condition that he would sign off on any specific operation to kill Soleimani. On this basis, it explains why Soleimani was given as a option for Trump following the attacks on the American embassy in Iraq and the death of an American contractor, according to NBC.
The alleged prior knowledge Trump had may undermine the official claim that Soleimani was planning imminent attacks on Americans. "There have been a number of options presented to the president over the course of time," according to a  senior administration official said, who noted it was "some time ago" that the president's aides discussed assassinating Soleimani on a list of potential retaliatory responses to Iranian aggression.
The report also noted that US intelligence have been tracking Soleimani for many years, and with Secretary of State Mike Pompeo's urging, discussed the possibility of retaliating against Soleimani after Pompeo revealed intelligence that showed the existence of "very serious threats that didn't come to fruition."
Moreover, talks of killing Soleimani were also brought up in 2017 between Trump and then national security adviser Army Lt. Gen. H.R. McMaster, later becoming more serious upon John Bolton taking over the position, the latter of whom resigned following policy disagreements between him and the Trump administration. 
Under Bolton's advice, Trump declared the entire IRGC organization as a terrorist group, equivalent to organizations such as Islamic State and al-Qaeda.
The Quds Force within the IRGC was originally designated as a foreign terrorist organization in 2007 under the Bush administration.