Ivanka Trump found out about her father's transgender ban in a notification on her phone. Sean Gallup/Getty Images

Ivanka Trump apparently had no idea that her father, President Donald Trump, was planning on announcing a ban on transgender people serving in the military, Politico reported.

Several White House aides told Politico that Ivanka and her husband Jared Kushner — who both serve as top advisers to the president — were "blindsided" by the announcement, and that Ivanka only found out about it when Trump tweeted it out last Wednesday.

Ivanka Trump was reportedly surprised by Trump's decision, given that he has supported LGBT rights in the past. He notably reached out to the LGBT community during his acceptance speech at the Republican National Convention last July.

"As president, I will do everything in my power to protect LGBTQ citizens from the violence and oppression of a hateful foreign ideology," he told the crowd, adding, "And, I have to say, as a Republican, it is so nice to hear you cheering for what I just said."

Trump also expressed his support for LGBT rights last June, tweeting, "Thank you to the LGBT community! I will fight for you while Hillary brings in more people that will threaten your freedoms and beliefs."

The president's tweets announcing the ban on transgender military servicemembers came a few weeks after Ivanka Trump publicly expressed her support for LGBT rights. "I am proud to support my LGBTQ friends and the LGBTQ Americans who have made immense contributions to our society and economy," she tweeted during pride month.

Many Pentagon officials, including Defense Secretary James Mattis, were reportedly unaware of the plan, as well, and General Joseph Dunford, chairman of the Joint Chiefs of Staff, said in a statement on Thursday that the military will not move forward with such a ban unless the president sends them written implementation guidance.