US President Donald Trump has ordered senate majority leader Mitch McConnell to "go nuclear" if Democrats attempt to block his Supreme Court nomination.

The Republican announced Neil Gorsuch as his pick for the Supreme Court, and he fills the vacancy left by the death of Antonin Scalia in 2016. He has suggested McConnell should force the nomination through.

Scalia died during Obama's tenure in office, in February 2016, but his Supreme Court nomination, Merrick Garland, was blocked by Republicans. GOP members wanted to wait until after the presidential election in the hope a Republican candidate would win and thus make a more conservative choice for the bench.

As such, the GOP is now worried Trump's nomination will be blocked by Democrats, with some keen to make it as difficult as possible to get Gorsuch confirmed, The Hill reported.

However, Trump has suggested he has instructed Senate majority leader Mitch McConnell to take strong action to prevent his nomination being blocked.

"If we end up with that gridlock, I would say, if you can, Mitch, go nuclear," Trump said at a meeting with judicial advocates.

"Because that would be an absolute shame if a man of this quality was put up to that neglect, so I would say, it's up to Mitch, but I would say go for it."

It is not clear whether McConnell would opt to force Gorsuch's nomination through the senate by abolishing the filibuster – meaning just 51 votes would be needed to confirm the nomination, as opposed to the 60 needed if Democrats filibuster.

If McConnell opted for such a strategy, it would spark concern from both Democrats and Republicans as it would break with precedent and a similar manoeuvre could be used against either party in future.