WASHINGTON, Dec 7 - The White House says President Joe Biden told Russian President Vladimir Putin on Tuesday that the United States is prepared to launch strong economic measures should Russia invade Ukraine, CNN reported.

This signals that these new measures would pack a bigger punch than the sanctions issued in 2014 that failed to stop Russia from occupying Crimea.

"I will look you in the eye and tell you, as President Biden looked Putin in the eye and told him today, that things we did not do in 2014 we are prepared to do now," national security adviser Jake Sullivan told reporters Tuesday afternoon after Biden's call with Putin.

During the last several months, Russia has erected supply lines, including medical units and fuel, which could sustain a drawn-out conflict should Moscow choose to invade Ukraine, two sources familiar with the latest intelligence assessments told CNN. And recent US intelligence findings estimate Russia could begin a military offensive in Ukraine in a matter of months as it amasses up to 175,000 troops along the border. Sullivan said the administration still believes Putin has not made a decision on whether to launch a military offensive against Ukraine.

Sullivan did not go into specifics, but added that the US is coordinating with European allies "at a deep level of specificity."

He said Biden "was direct and straightforward with President Putin, as he always is," later adding that "there was a lot of give and take. There was no finger-wagging, but the President was crystal clear about where the United States stands on all of these issues."

Along with the economic ramifications mentioned on the call, Sullivan said Biden relayed that the US is prepared to bolster defense capabilities in the region.

"He reiterated America's support for Ukraine's sovereignty and territorial integrity. He told President Putin directly that if Russia further invades Ukraine, the United States and our European allies would respond with strong economic measures," Sullivan said. "We would provide additional defensive material to the Ukrainians above and beyond that which we are already providing, and we would fortify our NATO allies on the eastern flank with additional capabilities in response to such an escalation."

The other option, Sullivan said, is de-escalation and diplomacy.

"The United States and our European allies would engage in a larger discussion that covers strategic issues, including our strategic concerns with Russia and Russia's strategic concerns. We managed to do this at the height of the Cold War and we developed mechanisms to help reduce instability and increase transparency," he said.

Biden and Putin spoke for about two hours over a secure video call earlier Tuesday.

US officials in recent days have weighed whether to issue wide-reaching sanctions on Russia meant to deter Putin from launching an invasion into Ukraine. They include new actions against members of Putin's inner circle and on Russian energy producers, and one potential "nuclear option" -- disconnecting Russia from the SWIFT international payment system used by banks around the world. (cnn/ez)