Democratic presidential nominee Joe Biden will speak in Philadelphia on Sunday about his rival President Donald Trump's plan to name a third justice to the Supreme Court, a move that would cement a 6-3 conservative majority.

Trump on Saturday said he will make his nomination this week and named Amy Coney Barrett of the Chicago-based 7th Circuit and Barbara Lagoa of the Atlanta-based 11th Circuit as possible candidates to fill the vacancy created by Friday's death of liberal icon Ruth Bader Ginsburg.

The passing of Ginsburg upended the November election contests, energizing both Trump's conservative base - eager to see the court overturn the 1973 Roe v. Wade decision that legalized abortion nationwide - and presenting new complications in the battle for control of the US Senate.

"I will be putting forth a nominee next week. It will be a woman," Trump said at a campaign rally in Fayetteville, North Carolina, where supporters chanted "fill that seat." "I think it should be a woman because I actually like women much more than men."

Biden, who stayed out the public eye on Saturday, will speak at about 2 p.m. ET (1800 GMT), his campaign said.

Trump needs Senate approval for any pick, but his fellow Republicans hold a 53-47 majority and Majority Leader Mitch McConnell has made confirming judges a top priority.

Democrats are still seething over the Republican-controlled Senate's refusal in 2016 to act on Democratic President Barack Obama's Supreme Court nominee, Merrick Garland, to replace conservative Justice Antonin Scalia, who died 10 months before that election.

At the time, McConnell said the Senate should not act on a nominee during an election year, but he and other top Republican senators have since reversed that stance.

They have time: While elections are on Nov. 3, a new Congress won't be sworn in until Jan. 3, with the winner of the presidential contest sworn in on Jan. 20.

'LUST FOR POWER'

Republican Senator John Barrasso on NBC's "Meet the Press" on Sunday brushed off Democratic complaints about the nomination process.

"Let's be very clear - if the shoe were on the other foot and the Democrats had the White House and the Senate, they would right now be trying to confirm another member of the Supreme Court," Barrasso said.

Democrat Hillary Clinton, whom Trump defeated in the 2016 election, on the same program called that view "indefensible."

"What's happening in our country is incredibly dangerous," said Clinton, a former secretary of state whose husband, Bill Clinton, nominated Ginsburg to the court in 1993. "Our institutions are being basically undermined by the lust for power."

Embattled Republican Senator Susan Collins of Maine on Saturday said the Senate should hold off on voting on a nominee, saying she believed the winner of the presidential election should have the chance to nominate Ginsburg's successor.

That made her the most notable member of her party to break with McConnell. Senator Lisa Murkowski in an interview with media in her home state of Alaska hours before Ginsburg's death was reported also said she believed it was too late in an election cycle to confirm a new justice; since Ginsburg's death she has not spoken publicly.

Trump has already appointed two justices: Neil Gorsuch in 2017 and Brett Kavanaugh in 2018. Kavanaugh was narrowly confirmed after a heated confirmation process in which he angrily denied accusations by a California university professor, Christine Blasey Ford, that he had sexually assaulted her in 1982 when the two were high school students in Maryland.

'NOTHING IS OFF THE TABLE'

Republicans risk the possibility of liberals embracing more radical proposals should Trump replace Ginsburg but Democrats win November's election, with some activists on the left suggesting even before Ginsburg's death that the number of justices on the court should be expanded to counter Trump's appointees.

"Let me be clear: if Leader McConnell and Senate Republicans move forward with this, then nothing is off the table for next year," Senate Minority Leader Chuck Schumer told fellow Democrats on a Saturday conference call, according to a source who listened to the call.

House of Representatives Judiciary Committee Chairman Jerrold Nadler on Saturday said that rushing a court pick through the Senate if Democrats win in November would be "undemocratic."