Trump told Boakai he speaks "such good English", asking where he went to school.
President Boakai says the move is intended to show "solidarity" with Liberians who are struggling financially.
Joseph Boakai tells the BBC he is trying to change the mindset of those who think government is a way to get rich.
At least three have died after a car hit people cheering Joseph Boakai's presidential election win.
Joseph Boakai urges fellow opposition candidates to join the "rescue team for a resounding victory".
With nearly all votes counted, President George Weah and his Joseph Boakai are running neck and neck.
With 73% of the votes counted, President George Weah and Joseph Boakai are both on 43%.
Turn-out was reportedly high in Tuesday's tightly contested presidential and parliamentary poll.
President George Weah is facing a strong challenge from the opposition in his bid for a second term.
