(NewsNation Now) — The Pentagon has placed 8,500 military personnel on “heightened preparedness to deploy” to bolster NATO forces amid Russian aggression toward Ukraine.

Pentagon press secretary John Kirby said Monday afternoon no final decisions have been made on deployments and that the order is about ensuring that the U.S. is ready to respond if NATO decides to deploy its response force.

“What this is about is reassurance to our NATO allies,” Kirby said, adding that no troops are intended for deployment to Ukraine itself.

Kirby said Defense Secretary Lloyd Austin recommended to Biden that up to 8,500 troops be ordered to prepare for potential deployment to Europe in light of signs that Russian President Vladimir Putin is not de-escalating his military pressure on Ukraine. Kirby said he was not prepared to identify the U.S.-based units because they were still being notified.

Kirby responded to NewsNation in a press conference, saying, “What we’re telling these units to do is to be ready to go on a shorter timeline than what they were before. We are not deploying them now.”

“We are not saying diplomacy is dead,” Kirby continued. “You heard secretary Blinken talk about this on Sunday in many outlets that he still believes there’s room for discussion and dialogue. We absolutely still believe that there’s time and space for that. And frankly, the Department of Defense fully supports that as being the way forward here, the way to a solution that deescalates the tensions.”

“It would be irresponsible if given the indications that we have — that there is no intent by the Russians right now to deescalate — and given that it takes a matter of time to get units more ready to go on a shorter timeframe, it would be irresponsible if we didn’t think about making sure that they had plenty of time to prepare and that’s all we’re doing at this point,” Kirby said.

The Pentagon’s move comes as tensions have soared between Russia and the West over concerns that Moscow is planning to invade Ukraine, with NATO outlining potential troop and ship deployments, Britain saying it would withdraw some diplomats from Kyiv, and Ireland denouncing upcoming Russian war games off its coast.

“We’ve always said we would reinforce our allies on the eastern flank, and those conversations and discussions have certainly been part of what our national security officials have been discussing with their counterparts now for several weeks,” said White House press secretary Jen Psaki.

Prior to the U.S. announcement, the Western alliance’s statement summed up moves already described by member countries, but restating them under the NATO banner appeared aimed at showing resolve. The West is ramping up its rhetoric in the information war that has accompanied the Ukraine standoff.

The Associated Press contributed to this report.