US deploys new type of nuclear weapon seen as key to countering Russia

The US military has deployed a new low-yield submarine-launched nuclear weapon, something that the Pentagon is viewing as critical to counter the threat posed by Russia's arsenal of smaller tactical missiles.

Several former high-ranking administration officials, however, said that the new weapons may increase the potential for confrontation, CNN reported.

"The US Navy has fielded the W76-2 low-yield submarine-launched ballistic missile warhead," John Rood, the under secretary of defence for policy, said in a statement on Tuesday (local time).

The new nuclear weapon is a modification of the pre-existing W-76 warhead, which is used to arm submarine launched Trident II (D-5) missiles, so the new weapon does not add to the total number of nuclear weapons in the US stockpile.

The nuclear launch codes and nuclear options in the so-called football for the President have now been updated to reflect this weapon, a US official confirmed to CNN.

The new warheads were first produced in February of last year.

The less powerful weapon was invoked in the Nuclear Posture Review 2018 of the Trump government, warning that opponents could believe they could use a smaller nuclear weapon against the US or their allies without fear that the US would have nuclear retribution would launch because American weapons are disproportionately more destructive.

Russia is believed to maintain a large stockpile of "tactical" nuclear weapons, which are less powerful and destructive than those possessed by the US.

The US does have some older tactical nuclear B61 "gravity" bombs, but these are seen as much more vulnerable than a submarine-launched weapon.