“Yesterday was the saddest day of my life since the death of my mother. But today is the happiest day of my life,” Lopetegui said as he fought back tears.
“We are convinced that we acted in an absolutely honest and clear way.”
Spain’s World Cup preparations were thrown into turmoil on Wednesday after Real Madrid confirmed Lopetegui would take over at the Bernabeu for the next three seasons, catching the Spanish Football Federation by surprise.
Spain players reportedly resisted his sacking, which came as Spain are due to face European champions Portugal in Sochi on Friday before taking on Iran and Morocco in Group B of the tournament.
There were fears Lopetegui’s appointment by the European champions could open up old divisions between the Real Madrid and Barcelona factions in the Spain squad.
Real Madrid president Florentino Perez called the Spanish football federation’s reaction to the club’s signing of Lopetegui “disproportionate” and “unfair” at his presentation on Thursday.