It’s been about three weeks since Russia’s sham referendum to annex four regions in Ukraine. This week, Russian President Vladimir Putin said those areas are now under the protection of Russia’s nuclear arsenal and declared martial law.

When Russia illegally annexed Donetsk, Luhansk, Kherson and Zaporizhzhia, it essentially claimed sovereignty over 15 percent of Ukrainian territory.

Appearing on state-run media Wednesday, Putin said martial law would take effect in the four impacted regions on Thursday. The Russian president didn’t spell out exactly what steps would be taken, saying only that it was necessary to give “additional powers” to the heads of all Russian regions that are now, according to the Kremlin, under the protection of Moscow’s nuclear umbrella.

Kremlin Spokesman Dmitry Peskov told reporters the territories are now “inalienable parts” of the Russian federation.

It should be noted, however, Russia still hasn’t defined the borders of those “inalienable parts.” The Russians have been losing ground in all four regions since the Kremlin’s annexation ceremony in September.

Ukrainian forces are trying to move quickly to regain as much ground as possible ahead of winter, but the changing of the seasons might not be the only time constraint for Ukraine.

U.S. House Minority Leader Kevin McCarthy said this week if Republicans take control of the House in November, the U.S. won’t be writing any more blank checks for military aid to Ukraine.

Reuters contributed to this report.