Washington: The Trump administration plans to loosen constraints on the use of nuclear weapons and develop a more “usable”, low-yield nuclear warhead for US Trident missiles, according a report in the Guardian.

The news report quoted Jon Wolfsthal, a former special assistant to Barack Obama on arms control and non-proliferation, who claimed to have seen a draft of the new Nuclear Posture Review (NPR) that is expected to be revealed sometime after President Donald Trump’s State of the Union address in late January.

The NRP, set to be published by the Pentagon, will be the first update of America’s nuclear doctrine in eight years.

The final draft of the key strategy, according to Mr Wolfsthal, is pretty hawkish, despite the fact that some of the more aggressive suggestions from an initial variant have been dropped.

Mr Wolfsthal told the newspaper that he had seen a copy of the final draft of the NPR which proposed the creation of the new weapon as well as revising the terms of use for weapons which would include attacks against national infrastructure or nuclear sites. He also said that earlier drafts of the document had been even more extreme, with plans for the development of hyper-glide missiles that could travel at speeds of up to 25,000kph being dropped.

“My read is this is a walk-back from how extreme it was early on. It doesn’t have as much terrible stuff in it as it did originally,” Mr Wolfsthal told the Guardian. “But it’s still bad.

Since taking office, Mr Trump has been vocal in his support for nuclear weapons, having talked about increasing the US’ stockpile and also having threatened North Korea with “fire and fury like the world has never seen”. Mr Trump has also suggested he would build weapons that would breach the 1987 Intermediate-Range Nuclear Forces Treaty with Russia.