Sen. Marco Rubio officially declared himself as a presidential candidate for the 2016 election during a conference with donors Monday afternoon, hours before a political rally is set to take place in Miami. 

In his speech at the Freedom Tower  in New York City, he told the crowd: "My candidacy might seem improbable to some watching from abroad. In many countries, the highest office in the land is reserved for the rich and powerful. But I live in an exceptional country where even the son of a bartender and a maid can have the same dreams and the same future as those who come from power and privilege." 

Some of his goals include reforming immigration laws and repealing Obamacare, NPR reported.

In an effort to knock down his Democratic rival, Hillary Rodham Clinton, Rubio referred to the former first lady as "a leader from yesterday," according to CBS News.

The first-term Republican from Florida said that the future of the United States is in "tomorrow." 

The 43-year-old's announcement comes a day after Hillary Clinton, 67, entered the presidential run, and the timing has been said to put Rubio in Clinton's shadow. 

Rubio's competition for the Republican nomination is steep - including former Florida Gov. Jeb Bush - and he'll likely hear criticisms that he is too young and not ready to run the White House. 

The first-generation immigrant's pitch to garner voters centers on the American dream, and should he win, he would become the nation's first Hispanic president. 

Rubio is scheduled to return to the Senate to participate in a hearing about Iran on Tuesday.