Russia has asked NATO for guarantees that Ukraine will never be allowed to join the alliance, while also saying that the buildup of troops near its borders is making Russia nervous, a spokesman for Vladimir Putin told the BBC on Tuesday. The spokesman, Dmitri Peskov, also accused NATO of breaking an historical promise to not approach Russian borders. 

The comments come after Putin said that the U.S. would never "subdue" Russia.

German Foreign Minister Frank-Walter Steinmeier said during a joint press conference with his Russian counterpart, Sergei Lavrov, that he could see "no grounds for optimism" as fighting escalated in eastern Ukraine and that Europe and Russia were heading for "confrontation instead of cooperation."

Steinmeier also urged Russia to abide by the Minsk cease-fire agreement.

Peskov's suggestions that NATO are gradually approaching Russian borders are in conflict with multiple media reports that say Russia has begun a military buildup on the Ukraine side of the border. He claims that the alliance was "attempt[ing] to break the ... balance of power."

During a televised appearance, Putin explained to a group of pro-Kremlin activists that the U.S. wanted "to subdue us, solve their problems at our expense. They want to dominate and influence." 

While receiving a round of applause, Putin added: "No-one in history ever managed to achieve this with Russia, and no one ever will."

Putin believes that the continued assault on the Russian economy will only boost local Russian industries and is counterproductive for the West. 

The EU agreed Monday not to increase sanctions against the former Soviet state.