Vice President Kamala Harris and former first lady Michelle Obama are leading contenders for the Democratic Party's 2024 presidential nomination if President Joe Biden chooses not to run again, according to a new poll.

A Hill-HarrisX poll conducted from November 18 to 19 showed Harris and Obama ahead of other possible candidates, including Senators Bernie Sanders and Elizabeth Warren.

Harris is experiencing low approval ratings - even lower than Biden's - but she enjoyed a narrow lead over the former first lady with 13 percent of respondents saying they would support her if Biden isn't running.

Obama was supported by 10 percent of respondents, while the other candidates in the poll received the support of just 5 percent or less.

Those other candidates included Sanders and Warren as well as Senator Cory Booker, Secretary of Transportation Pete Buttigieg, Senator Cory Booker (D-NJ), former New York Mayor Michael Bloomberg and former New York mayoral candidate Andrew Yang.

However, the poll also showed that 36 percent of respondents said they were "unsure" who they would support and 13 percent said they would back a candidate who was not on the list provided.

The poll surveyed 939 registered voters and had a margin of error of 3.2 percent.

Biden has said he intends to run for a second term but concerns about his age combined with stubbornly low approval ratings have led to speculation about his plans. He will be 81-years-old at the time of the next presidential election in 2024.

As vice president, Harris may seem the obvious choice to succeed Biden as the Democratic candidate if the president opts not to seek a second term. However, Harris currently has a lower approval rating than Biden.

Poll tracker FiveThirtyEight, which monitors the vice president's approval based on analysis of a wide range of polls and its own system of pollster ratings, gave her an approval rating of just 40.5 percent as of November 22, compared to 51.9 disapproval.

By contrast, Biden's approval stood at 42.9 percent in FiveThirtyEight's analysis as of November 24, with 51.8 percent disapproval.

The White House has also recently tried to tamp down rumors of a rift between Harris and Biden amid a CNN report that the vice president felt constrained in what she could do during the first 10 months of the administration.

Michelle Obama, who is married to former President Barack Obama, has often been talked about as a potential presidential candidate but has never run for public office.

She was the most admired woman in a 2020 Gallup poll, with 10 percent of respondents mentioning her, followed by Harris on six percent and then first lady Melania Trump with four percent.

Gallup found the most admired man in 2020 was then President Donald Trump with 18 percent of respondents mentioning him, followed by former President Obama on 15 percent and Biden on six percent.

Recent polls have also shown Trump defeating both Biden and Harris in hypothetical 2024 matchups.

Update 11/27/21 07.09 a.m. E.T.: This article was updated to include more information.

A composite shows former first lady Michelle Obama and Vice President Kamala Harris. Obama and Harris enjoy leads in a poll of 2024 Democratic presidential candidates if President Joe Biden doesn't run.Getty Images