"I think that there was the 'Never Trump' movement and then there was Gov. Mitt Romney. He went out of his way to hurt Donald Trump. He gave two speeches that I can recall in this calendar year, and they were both about Donald Trump," Conway said on ABC's "This Week."
Conway did add that she is glad that the former Massachusetts governor and the president-elect are now talking.
Conway has taken to Twitter over the past week to express some of her views on Trump's choice for secretary of state, tweeting a story from Politico about Trump loyalists warning against Romney as secretary of state and saying she was receiving "a deluge" of similar comments.
She also tweeted: "Kissinger & Schultz as Secs of State flew around the world less, counseled POTUS close to home more. And were loyal. Good checklist."
Conway said, "There's one person that will select his cabinet, and it's President-elect Donald Trump. Whatever he decides will have my full support and respect and he knows that."
She noted that Romney is one contender among others being considered for secretary of state.
"We're all for party unity. I don't think a cost of admission for party unity has to be the secretary of state position," Conway said.
Conway also said President-elect Trump is "open to researching and, in fact, resetting relations with Cuba" after the death of longtime Cuban leader Fidel Castro.
During the campaign, Trump pledged to reverse President Obama's executive actions on Cuba, which have among other things allowed direct flights between the two countries and lifted restrictions on rum and cigar imports.
That pledge may not be set in stone, however, as Conway said Trump is "open to any number of possibilities."
Either way, Trump wants to change the current arrangements because the U.S. did not get enough out of them, Conway said.
Trump's "criticism of what has happened in the last couple of years is very simple, it's that we got nothing in return," she explained, adding that "by reopening diplomatic relations with Cuba, allowing commercial aircraft and the rest, that we really got nothing in return."
"We just can't romanticize Fidel Castro now that he's gone," she said.