Trump has said he'll announce his selection Monday in a prime-time event from the White House East Room at 9 p.m.
Democratic Sen. Richard Blumenthal accused Trump of outsourcing his decision to the Federalist Society and other conservative groups.
Reuters reported last week that conservative federal appeals court judges Kethledge and Brett Kavanaugh were the two most serious contenders being considered by Trump for the Supreme Court, citing a source familiar with the process.
He said Kavanaugh would be his top choice to replace retiring Justice Anthony Kennedy.
While final nominees will be known only when Mr Trump makes the announcement, this would be for the second time that Mr Thapar might not be able to make it to the final cut after being interviewed by Trump.
Amul Thapar is the US' first Article III judge of South Asian descent.
Katharine McPhee and David Foster Are Engaged
Despite the couple's age difference, McPhee is well-liked by Foster's family, who apparently think the two are a fine match. It's unclear exactly which day he proposed, but we imagine it was shortly before this pic was taken.
Battle lines have been drawn over the future of abortion in America on the eve of President Trump's nomination of a second justice to the U.S. supreme court that could put the landmark 1973 ruling Roe v Wade in jeopardy.
Trump during his campaign in 2016 said he would appoint justices who would overturn the landmark 1973 decision that said women have a constitutional right to an abortion. "We've been talking about this for 36 years, going all the way back to the nomination of Sandra O'Connor", he said. This will be 6.30 am IST, 10 July.
"Let's say it's the four people", Trump said.
"I think of the four people, I have it down to three or two". I do think the president has to think about who is the easiest to get confirmed here. All but one of the 25 people on the list are members of The Federalist Society, a national organization of conservative lawyers, and there's a clear pattern to judicial nominees being fed by the group: They are young, conservative and have records of being very opposed to abortion rights. "The whole list is extraordinary", he said. We'll announce it on Monday. "I'll give you the answer", Mr Trump said. He was confirmed by the Senate 52-44.