Republican National Committee Chairman Reince Priebus said Wednesday that Vice President Joe Biden, if he decides to run for president, would be a more formidable candidate than current Democratic front-runner Hillary Clinton.

"I think he's probably tougher. Hillary Clinton has a lot of problems. I think she is an opponent that's easy to define," Priebus told the "Today" show's Savannah Guthrie.

"I think Joe Biden is someone that a lot of people, whether they like his politics or not, they like him," Priebus said, adding that it's important because "likability is probably the number one issue on the ballot."

In an NBC/Wall Street Journal poll released this week, Clinton's approval rating dropped eight points from last month to its lowest level since 2008. Just 37 percent of all Americans said they view Clinton favorably, compared to 48 percent who have a negative view. Biden was not included in the poll.

Priebus' comments come amid ongoing speculation that Biden will enter the race. Following the death of Biden's son earlier this year, presidential discussions were largely placed on hold and Biden even reportedly considered resigning from office to better help his family grieve. But as The New York Times reports, Biden and his associates are now actively exploring a possible run, something that his son encouraged him to do from his death bed.

A recent survey from Quinnipiac University found that 13 percent of Democratic voters nationwide back Biden. Clinton still leads the pack with 55 percent, followed by Vermont Sen. Bernie Sanders with 17 percent. The pollsters found that Biden runs just as well against top Republicans as Clinton does. Moreover, Biden had higher favorability ratings than Clinton, 49 percent to 40 percent.

Those familiar with Biden's plans said he is expected to make a final decision by early September, according to PBS.