NEW YORK, July 13. /TASS/. Former US President and Republican presidential hopeful Donald Trump has invited incumbent President Joe Biden, his main opponent in the race, to take a cognitive test together.

"Joe should immediately take a cognitive test, and I will go with him, and take one also. For the first time we’ll be a team, and do it for the good of the country," he wrote on the Truth Social media platform. "And from now on, all presidential candidates should be mandated to take a cognitive test and aptitude test, regardless of their age," Trump added.

The US will hold its presidential election on November 5. Trump has already secured the Republican presidential nomination. Biden, who is seeking a second term in office, has won enough delegates to get the Democratic nomination. Both were expected to be approved as presidential candidates at their parties’ conventions but after Biden’s failure in the June 27 election debate with Trump, calls are growing louder for Biden’s withdrawal from the race.