President Trump endorsed Rep. Mike Collins, R-Ga., for Senate in Georgia.

Trump called in a "very successful businessman" and a fighter for the America First Agenda. 

"Mike, who like me is all about AMERICA FIRST, is running against a Radical Left Dumocrat named Jon Ossoff, a weak and pathetic Senator who tried to raise Taxes by over 4 Trillion Dollars, and voted against all of our Tax Cuts, including NO TAX ON TIPS, NO TAX ON SOCIAL SECURITY, and NO TAX ON OVERTIME," he wrote on Truth Social.

"Ossoff voted for Men in Women’s Sports, Transgender for Everyone, Open Borders, and Record High Taxes that, under Crooked Joe Biden, destroyed the American Economy, including 401(k)s and Market Numbers, which are now at the highest point, EVER!" he added.

Trump tore into Ossoff's stance on illegal immigration issues.

"He is an Open Border Advocate wanting Criminals of every variety, including 11,888 Murderers, to pour into our Country totally unchecked and unvetted. We are the opposite!" he wrote.

"I created the Strongest Border in History, and Congressman Mike Collins backed me up all the way. Jon Ossoff wants to abolish our Borders, stop deporting Criminal Illegal Aliens, and supports dangerous 'Soft on Crime' Policies like cashless bail, that let repeat Violent Criminals roam free on our streets," he added.

Gov. Brian Kemp, R-Ga., has been campaigning with Collins' GOP primary opponent, Derek Dooley. 

The runoff election takes place on June 16.