Vice President Kamala Harris on Thursday rejected criticism from Republican presidential candidates who have ramped up their attacks on her as the 2024 campaign for the White House gets underway, saying their jabs are "not new" and come as the Biden administration has delivered on its policy goals.

"We're delivering for the American people. And the reality of it is that, unfortunately, very few of those who challenge our administration actually have a plan for America," Harris said in an interview with "Face the Nation" moderator and chief foreign affairs correspondent Margaret Brennan from Jakarta, Indonesia, where the vice president attended a summit of Southeast Asian countries.

Harris highlighted the administration's success in capping the cost of prescription drugs and the monthly cost of insulin to $35 per month for Medicare beneficiaries — policies enacted after congressional Democrats passed their sweeping climate, tax and health care bill last year — as well as its jobs record, including the creation of more than 800,000 manufacturing jobs.

"This is the work under Joe Biden's leadership that has actually been accomplished," she said. "And I think the American people most of all, want a leader who actually gets things done. And that is what Joe Biden has accomplished."

Harris, the first woman elected vice president, was asked about recent attacks on her from numerous Republicans vying for the party's presidential nomination, who have used the prospect of Harris succeeding Mr. Biden as commander-in-chief as part of their pitch to voters.

Nikki Haley, the former Republican governor of South Carolina and U.S. ambassador to the United Nations, has claimed, "a vote for Joe Biden is a vote for Kamala Harris," while Florida Gov. Ron DeSantis, trailing frontrunner Donald Trump, has called Harris "impeachment insurance."

But Harris said the attacks are "nothing new" and listed the barriers she has broken throughout her career, including becoming the first woman district attorney in San Francisco and the first Black woman to serve as attorney general of California.

"They feel the need to attack because they're scared that we will win based on the merit of the work that Joe Biden and I, and our administration has done," she said.

While Republicans continue to lambaste Harris, some Democrats are concerned about Mr. Biden's age: A Wall Street Journal poll found two-thirds of Democrats said the president is too old to run again. If reelected, Mr. Biden would be 82 when he begins a second term. 

Asked whether she is prepared to be president, Harris replied, "Yes I am, if necessary." But the vice president lauded Mr. Biden's leadership over his first term in office.

"Joe Biden is going to be fine. Let me tell you something: I work with Joe Biden every day," she said. "The work that under Joe Biden's leadership our administration has accomplished is transformative."

A previous version of this video clip was edited incorrectly. Watch the full exchange between Margaret Brennan and Vice President Kamala Harris, relating to Republican attacks and Democratic concerns about the Biden/Harris reelection campaign, in the player above.