The 24-year-old striker, who can also play in midfield, has impressed Simon Grayson and his management team during a month-long trial.
Leeds have received a work permit for Nunez, who appeared for Honduras during this summer's World Cup finals in South Africa, starting two group games and appearing as a substitute in another.
He has played most of his professional football in the United States, but was most recently with Honduran league side Olimpia.
Source: PA
Source: PA