"In our interview last week with President Trump, he questioned whether his Democratic opponent, Joe Biden, could handle a similar encounter," Wallace reminded his viewers.
"This week, we asked the Biden campaign for an interview and they said the former vice president was not available," he continued.
"We'll keep asking every week."President Donald Trump, who posted to Twitter a video clip of Wallace calling out the Democrat, accepted his invitation last Sunday.
As Wallace pointed out, during his appearance on Fox News Sunday, Trump questioned Biden's fitness for office, arguing that the Democratic Party's presumptive presidential nominee would not be able to handle a similar grilling.
"Let Biden sit through an interview like this, he'll be on the ground crying for mommy. He'll say, 'Mommy, mommy, please take me home,'" the commander-in-chief told Wallace.
Trump suggested that the Democratic nominee is being hidden away in the "basement" of his Delaware home because members of his campaign know that he is cognitively impaired.
Although he refused to explicitly say that Biden suffers from dementia, he argued that the former vice president "doesn't know he's alive."
To lead the country, "you have to be sharp and tough and so many other things," he asserted.
Trump also dared his opponent to take a cognitive test, claiming to have passed one with flying colors. Even after Wallace pointed out that the test seemed very easy, he insisted that Biden would not pass it.
As Fox News noted, Wallace's revelation that Biden refused to be interviewed comes after months of Republicans hitting the former Delaware senator for "hiding" from the public.
Unlike Trump, Biden has largely avoided public appearances and interviews with the press, seemingly running a low-key campaign as Trump struggles to deal with the devastation caused by the coronavirus pandemic.
Momentarily, the Democrat has no reason to change his strategy. As the publication wrote, in recent weeks, Biden has increased his polling lead over Trump, surging ahead nationwide and in key battleground states.
Averages of polling data suggest that the former Delaware senator is ahead by a comfortable margin in Michigan, Wisconsin, Florida and Pennsylvania. In 2016, when he competed against former Secretary of State Hillary Clinton, Trump won all four states. Additionally, Trump is trailing his opponent in Arizona, North Carolina and Ohio. Some polling even suggests that he is also struggling in traditionally Republican states such as Texas and Georgia.