Trump made his announcement Wednesday on Twitter.

Trump's decision is a crucial one that could shape US law on major issues like abortion for decades.

One of the court's nine seats has been vacant since conservative justice Antonin Scalia died in February 2016.

In the interim, Senate Republicans refused to give President Barack Obama's nominee, Merrick Garland, even a confirmation hearing, much less put the nomination to a vote.

So the court has been divided evenly between progressives and conservatives. That equality however runs the risk of the court deadlocking.

Trump has said he wants a candidate who is against abortion and firmly backs Americans' right to own guns.