The US is updating its nuclear arsenal amid growing security fears

• The US Department of Defense announced plans to build a new gravity bomb.
• The new variant will be part of the B61 models that were first introduced in the 1960s.

The Department of Defense announced Saturday the US plans to add a new model of nuclear bomb to its arsenal.

The new gravity bomb will be called B61-13, a variant on the existing B61 model that was first introduced in the 1960s. The Department of Energy's National Nuclear Security Administration will begin production pending Congressional authorization and appropriation, according to a Department of Defense statement.

The previous model, B61-12, can carry out earth-penetrating attacks, low-yield and high-yield attacks, above surface detonation, and bunker-buster options, Insider previously reported.

The move is the result of a "changing security environment" and not any specific event, according to a fact sheet provided by the department.

The announcement comes just one week after the US announced a worldwide caution travel advisory amid the Israel-Hamas war.

"Due to increased tensions in various locations around the world, the potential for terrorist attacks, demonstrations or violent actions against US citizens and interests, the Department of State advises US citizens overseas to exercise increased caution," the warning read.

The US last issued a worldwide caution alert in August 2022 following the killing of al-Qaeda leader Ayman al-Zawahiri, per CNN.

Todd Brown, a retired senior State Department official, told CNN the current climate "surpasses anything I have seen before in the lease with the potential to get even worse."