WASHINGTON (Reuters) - Michelle Obama will travel to Liberia, Morocco and Spain with her teen daughters Malia and Sasha at the end of June to promote education for girls, one of her signature issues as the first lady of the United States, the White House said on Wednesday.

In Liberia, Obama will visit a Peace Corps training center in Kakata and a school in Unification Town to talk to young women about barriers they face to staying in school. She will be joined by Liberian President Ellen Johnson Sirleaf, the White House said.

Obama will be joined by actor Meryl Streep in Morocco on June 28 and 29 to talk about commitments made by the U.S. government and the Kingdom of Morocco to help girls go to school.

On June 30, Obama will wrap up the trip by giving a speech in Madrid about her "Let Girls Learn" global initiative, a push to harness government and private sector resources to promote education for girls, the White House said.

(Reporting by Roberta Rampton; Editing by Tom Brown)