WASHINGTON (Reuters) - The Biden administration plans to impose new restrictions on firearms exports and increase scrutiny on transactions to limit diversions of guns to drug cartels, criminal groups, gangs and others, a Commerce Department official said late on Thursday.

The department on Oct. 27 issued a pause on most firearm exports to assess the "risk of firearms being diverted to entities or activities that promote regional instability, violate human rights, or fuel criminal activities."

The department plans to announce on Friday it will lift the pause from May 30 when the new restrictions take effect. They are being imposed because the department believes it needs to do more prevent exported firearms from being diverted for malign purposes and harming U.S. national security, the official said.

The Commerce Department expects the restrictions to result in about a 7% reduction, or $40 million, out of the $600 million in average annual U.S. firearm exports, the official said.

The new interim final rule will impose restrictions on exports to non-governmental users in 36 countries where the State Department has determined they are at high risk of diversions or misuse.

The department will revoke some export licenses and will cut some from four years to one-year licenses, the official said.

The 36 countries include some former Soviet Republics, the official added, saying it is "increasing scrutiny on a transaction by transaction level to ensure that firearms aren't exported to destinations of concern."

Bloomberg News reported the plan earlier.

The Oct. 27 pause on export licenses for firearms and ammunition sales to non-governmental users had some exemptions, including export licenses for Ukraine and Israel, and some other close allies.

In November, 46 Republican senators said they had "significant concerns" about the pause, saying it "puts at stake U.S. commercial and economic interests" as well as U.S. national security and foreign policy. A similar letter was sent by House Republicans.

(Reporting by David Shepardson; Editing by Sonali Paul)

By David Shepardson