U.S. President Barack Obama is in final stages of consideration for a long-delayed Nuclear Posture Review this week, and radical changes could be added to the review, according to media reports on Tuesday.

Obama summoned Defense Secretary Robert Gates to the White House Monday afternoon, and the New York Times reported Gates presented Obama several options during the meeting. The paper also said Obama is considering permanently reducing U.S. nuclear weapons arsenal, but rejected proposals that the United States declare it would never be the first to use nuclear weapons.

The Nuclear Posture Review, originally due to be sent to Congress last December, was delayed several times, most recently this month, when its release date was pushed back to later this month instead of March 1. Reports indicated the delay revealed differences between the White House, which wanted big changes, and the Pentagon, which was working on a "continuation of the status quo," according to Defense News.

Reports also said the White House wants what is called "Prompt Global Strike" ability, a non-nuclear option which can hit targets anywhere in the world in less than an hour.

Steven Pifer, an arms control expert with the Brookings Institution, said that Prompt Global Strike ability is basically putting conventional warheads instead of nuclear warheads in ballistic missiles, giving the United States ability to hit elusive targets such as al-Qaida leader Osama bin Laden within an hour's notice.