The Pentagon accused Russia of expanding its role in the Libya war by sending fighter jets there to boost Moscow-linked mercenaries on the side of warlord Khalifa Hifter, The Washington Post reported Tuesday.

The U.S. Africa Command said in a strongly worded statement “Russian fighter aircraft arrived in Libya, from an airbase in Russia, after transiting Syria where it is assessed they were repainted to camouflage their Russian origin.”

U.S. Africa Command commander Gen. Stephen Townsend said “Russia is clearly trying to tip the scales in its favor in Libya. Just like I saw them doing in Syria, they are expanding their military footprint in Africa using government-supported mercenary groups.”

He added, “Russia has [long] denied the full extent of its involvement in the ongoing Libyan conflict. Well, there is no denying it now. We watched as Russia flew fourth generation jet fighters to Libya . . . private military companies [cannot] arm, operate, and sustain these fighters without state support – support they are getting from Russia.”

Hifter, who is attempting to oust Tripoli’s  U.N.-backed government, launched an offensive on the capital last year, with hundreds of Russian mercenaries fighting since September alongside his forces, according to the Post.

But almost all the mercenaries departed over the weekend after Hifter’s forces suffered losses in western Libya.

Andrei Krasov, deputy head of the defense committee in the lower house of Russia’s parliament, denied Moscow has sent military planes to Libya, calling it an attempt by the U.S. to “play the Russia card,” emphasizing Russia’s position is well known: It wants “all conflicting parties not to use force but to begin negotiations.”