The development and deployment of small tactical nuclear weapons have been proposed during an ongoing review of U.S. nuclear policy by the administration of President Donald Trump, a congressional source said Sunday.

Adoption of the proposal would mark a major departure from the previous administration of President Barack Obama that sought "a world without nuclear weapons."

Tactical nuclear weapons of several kilotons are seen as usable as their destructive power is limited compared with conventional nuclear weapons. But it remains uncertain whether Washington will employ such an option, given strong opposition within the U.S. government, the source said.

The proposal has emerged at a time when the United States is struggling to deal with the growing nuclear threat from North Korea.

Trump ordered the crafting of the Nuclear Posture Review in January, the first since one under the Obama administration in 2010.

The U.S. government is planning to complete the review by the end of this year, taking new security conditions into account.

Discussions on the NPR are led by the U.S. Defense Department and the Energy Department. According to the source, some have voiced support for the development and deployment of small tactical nuclear weapons in view of North Korea as well as Russia, which has unveiled its policy to strengthen tactical nuclear forces.

With guided small tactical nuclear weapons, the United States could destroy nuclear facilities in North Korea while curbing radiation damage, the source added.

On the introduction of small tactical nuclear weapons, a U.S. government official said there are a number of options to build a flexible nuclear posture.

The same official also said it cannot be denied that the promotion of tactical nuclear weapons in the upcoming policy review could send a message that runs counter to disarmament.