Washington (CNN) Two key Republican senators who have been undecided on whether to vote to confirm Brett Kavanaugh described the FBI's findings of an investigation into President Donald Trump's Supreme Court nominee as a thorough report, contrasting with Democrats' objections that the inquiry was rushed and incomplete.

Republican Sen. Susan Collins of Maine said Thursday that the FBI probe into allegations of sexual assault and inappropriate sexual behavior against Kavanaugh seems to be "very thorough" and said she would read the findings in full later in the day.

"It appears to be a very thorough investigation," Collins, who has not yet indicated how she plans to vote on the nomination, told reporters in the Capitol.

Collins is among a handful of senators whose votes could decide the fate of the nomination. The Maine Republican -- along with Republicans Sens. Jeff Flake of Arizona and Lisa Murkowski of Alaska and Democratic Joe Manchin of West Virginia -- are under intense scrutiny for clues as to how they may vote on the nomination as Senate Republicans push for a final vote, which could happen as early as Saturday.

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