London mayor's spokesperson slams Trump's tweet as 'ill-informed'

The president said the U.S. "[needs] the Travel Ban" in response to the attacks.

Trump responded with a tweet, "At least 7 dead and 48 wounded in terror attack and Mayor of London says there is "no reason to be alarmed!"

A spokesperson for Khan, the city's first Muslim mayor, called Trump's remark "ill-informed" on Sunday and said it took the mayor's words out of context.

The executive order, now in its second version, has been blocked by the U.S. Court of Appeals for the 4th Circuit, which declined to lift a lower court's stay of the order.

Omar Jadwat, director of the ACLU's Immigrants' Rights Project and who argued the 4th Circuit case opposing the executive order, told ABC News that there isn't a comparable court case to the one against the travel order in part because of what Trump says on Twitter and in speeches.

"Ordinarily, it's hard to prove that things are done with an improper purpose because the decision makers cover their tracks with very careful wording," Jadwat said. "What Trump says about his own intentions is unusual."