Sen. John McCain, R-Ariz., wants President Obama to send "military assistance" to Ukraine to prevent Russian forces conducting "exercises" on its border from further invading the country.

Ukrainian officials say Russia has 100,000 troops along their border. "Considering President Putin's track record of lies and aggression, it is prudent now to expect and plan for the worst," McCain said in a joint statement with Sen. Lindsey Graham, R-S.C., calling for assistance.

"This assistance should include small arms, ammunition, and defensive weapons, such as anti-armor and anti-aircraft systems – as well as critical non-lethal support, such as protective equipment, medical supplies, spare parts, and intelligence sharing," the senators said.

The White House has so far been unwilling to send military aid to Ukraine, other than non-lethal items like rations. Earlier Friday, deputy national security adviser Ben Rhodes told reporters that he had "nothing new" to announce about the Russian troop buildup.

"We of course continue to be very concerned about the Russian deployments on the border that go well beyond any military exercise that they would need to do as part of their standard practice," Rhodes said during a Friday press gaggle. "So it’s something we’re watching very closely. But we haven’t seen any new development in terms of those troops."