Kamala Harris insists US will respond aggressively on Ukraine after Biden flub

Kamala Harris has joined in on the White House’s campaign to repair Joe Biden’s flub on Ukraine in his press conference on Wednesday, where he revealed Nato is divided on how to respond to a “minor incursion” from Russia.

“The president of the United States has been very clear, and we as the United States are very clear: if Putin takes aggressive action, we are prepared to levy serious and severe costs. Period,” Harris said in a Thursday morning appearance on NBC’s Today Show.

Related: Joe Biden thinks Russia will attack Ukraine – but will face a ‘stiff price’

Host Savannah Guthrie countered that the White House had been “less than clear”, issuing a statement just minutes after Biden’s press conference affirming the “united response” between the US and its allies.

“Savannah, I’m being clear with you right now. If you’re interested, I’ll continue to be clear,” Harris said in response.

During Wednesday’s two-hour press conference – his second solo press conference since taking office – Biden made surprising remarks on the decision Nato allies will face depending on the severity of a Russian incursion.

“What you’re going to see is that Russia will be held accountable if it invades, and it depends on what it does,” he said. “It’s one thing if it’s a minor incursion, and then we end up having to fight about what to do and not do etc.”

Asked to clarify what constitutes a minor incursion, Biden pointed to cyber-attacks and the presence of Russian intelligence officers.

“There are differences in Nato as to what countries are willing to do, depending on what happens,” Biden said. “If there’s Russian forces crossing the border … I think that changes everything.”

In a clarification issued 30 minutes after the end of the press conference, the White House press secretary, Jen Psaki, said: “If any Russian military forces move across the Ukrainian border, that’s a renewed invasion, and it will be met with a swift, severe and united response from the United States and our allies.”

The kerfuffle has alarmed the Ukrainian government, with one official telling CNN that Biden’s comment “gives green light to Putin to enter Ukraine at his pleasure”.

Harris went on the defense for Biden when Guthrie asked how “damaging” it was that Biden “openly talked about division within Nato countries and Nato allies”.

“I think your audience knows Joe Biden has been working as the former head of foreign relations, and as the former vice-president and a senator in a role of leadership on foreign policy, for years,” Harris said. “I have witnessed him continuously engage in direct and honest conversations with our partners and allies, and this is no exception.”