Democrat Hillary Clinton, who is running against Republican Donald Trump in the Nov. 8 presidential election, is expected to announce her running mate as early as Friday.
Here are some of the potential vice presidential candidates Clinton is considering, according to U.S. news media:
The U.S. senator from Virginia is a former Roman Catholic missionary and civil rights lawyer who is fluent in Spanish.
Kaine, a former Richmond mayor and former Virginia governor, has served on the Senate's Foreign Relations and Armed Services committees.
He has backed liberal causes such as establishing a pathway to citizenship for undocumented immigrants. But, like many Republicans and moderate Democrats, he has supported free-trade deals, a stance at odds with many party progressives.
The U.S. agriculture secretary is a former governor of Iowa.
During the primary, he campaigned enthusiastically for Clinton, speaking about his family's struggles with addiction and mental health. Clinton has promised to address those issues if elected.
Vilsack, a Pittsburgh native, was orphaned and adopted as an infant. He settled in his wife's home state of Iowa.
New Jersey's first black U.S. senator is a former Newark mayor. He was elected to the Senate in a 2013 special election and won re-election in 2014.
Booker campaigned enthusiastically for Clinton, including in the crucial early-voting state of New Hampshire during her primary race against Senator Bernie Sanders.
U.S. Senator Elizabeth Warren of Massachusetts is a fierce critic of Wall Street who spearheaded the creation of the U.S. Consumer Financial Protection Bureau after the global financial crisis. President Barack Obama tapped her to help set up the agency, but congressional Republicans blocked her appointment.
Warren is popular with progressives, and was urged to run for president in 2016 but declined.
She endorsed Clinton in June, then joined her on the campaign trail.
The retired Navy admiral and former supreme allied commander of NATO is the dean of the Fletcher School of Law and Diplomacy at Tufts University near Boston.
Stavridis worked closely with Clinton when he was at NATO and she led the State Department during Obama's first term.
Though Stavridis would bring military heft to Clinton's ticket, his role as a senior military official in the George W. Bush administration during the early years of the U.S. occupation of Iraq could provide Trump with a line of attack. Trump has criticized Clinton for, as a U.S. senator, voting for the 2003 U.S.-led invasion.
The U.S. senator from Ohio and former member of the U.S. House of Representatives is one of the Democratic Party's leading progressives.
Brown was an early opponent of the Trans-Pacific Partnership trade agreement sought by the Obama administration, describing it as a "giveaway to corporations."
Obama's labor secretary has championed changes in regulations popular with organized labor and progressives.
Perez reversed a regulation exempting domestic and home-care workers from overtime pay and extended overtime protections to some salaried workers by lowering the eligibility threshold.
Perez has little campaigning experience, however, having only held one term on a county council from 2002 to 2006.
The Department of Housing and Urban Development secretary is considered a rising Democratic star.
Castro has pushed for expanding opportunities while serving as housing secretary, including by broadening internet access across the country. But progressive groups have criticized his agency's sale of mortgage loans to big banks rather than nonprofits during his tenure.
A former San Antonio mayor, Castro was elected as the city's youngest councilman at the age of 26.