Blinken warns any Russian 'invasion' of Ukraine would be met with a 'severe and a united response'

US Secretary of State Antony Blinken warned that any Russian invasion of Ukraine would be "met with a severe and a united response" following his meeting Friday with Russian Foreign Minister Sergey Lavrov, the latest round of diplomatic talks that Blinken said provided a "clearer path of understanding each others' concerns."

"We didn't expect any major breakthroughs to happen today, but I believe we are on a clearer path in terms of understanding each other's concerns, each others' positions," Blinken said at a press conference after the meeting. "Let's see what the next days bring."

The Americans and Russians agreed to keep talking -- but on little else -- following the latest round of diplomatic talks.

Blinken said that the US would provide Russia with a written response next week to the concerns that it had publicly released, something that Moscow has sought.

"I told him that following the consultations that we'll have in the coming days with allies and partners, we anticipate that we will be able to share with Russia our concerns and ideas in more detail and in writing next week, and we agreed to further discussions after that," Blinken told reporters following his sitdown with Lavrov.

But Blinken reiterated that Moscow's central demand -- that the US and NATO commit to never admitting Ukraine as a member -- is simply a non-starter.

"We've been clear. If any Russian military forces move across Ukraine's border, that's a renewed invasion. It will be met with swift, severe and a united response from the United States and our partners and allies," Blinken said.