The U.S. is considering imposing "massive" sanctions if Russia invades Ukraine, according to the NATO ambassador.

• The U.S. ambassador to NATO, Julianne Smith, stated that the U.S. and its allies are still conveying to Russia that they are prepared to react if there is an escalation.
• Smith stated that there is no evidence to suggest that Russian President Putin has made a decision on how to handle the troops he has positioned near the Ukrainian border.
• She stated that they were attempting to narrow down the options for President Putin as he considered his choices.

The U.S. Ambassador to NATO, Julianne Smith, stated that the U.S. and its allies are prepared to respond to any Russian escalation, including through the imposition of "massive economic sanctions and consequences."

On Thursday, CNBC's Hadley Gamble was informed by her that they were considering all possibilities.

Smith stated that there is no evidence to suggest that Russian President Putin has made a decision on how to handle the troops he has positioned near the Ukrainian border.

She stated that they were attempting to narrow down the options for President Putin as he considered his choices.

The escalating tensions at the border have led to concerns of a conflict between Russia and Ukraine. Despite talks with the U.S. and other Western countries, there has been little advancement in negotiations. The threat of imposing sanctions has not persuaded Russia to de-escalate the situation.

Petro Poroshenko, the former president of Ukraine, stated that imposing sanctions on Nord Stream 2 would weaken Russia and deter Putin from launching an attack. Nord Stream 2 is a pipeline project that would transport gas from Russia to Europe by bypassing Ukraine.

The Kremlin has denied any plans to invade Ukraine, repeating its illegal annexation and occupation of Crimea in 2014.

Smith stated that the deployment of 3,000 U.S. troops near Ukraine was aimed at both reassuring regional allies and deterring potential aggression.

She argued that the numbers of Russian troops stationed near Ukraine's border are significantly higher, estimating around 127,000.

She remarked that we're comparing apples and oranges, stating that U.S. troops won't enter Ukraine or remain permanently in central and eastern Europe.