Over the past few weeks Madonna has been embroiled in a much publicised dispute with ex-husband Guy Ritchie over the custody of their 15-year-old son Rocco. While the singer is yet to openly address the situation, she did make an emotional speech during her concert in Mexico City on January 6th during which she referenced going through ‘challenging times’ in her life.

MadonnaMadonna has spoken of ‘challenging times’ during a recent concert.

"We all go through challenging times in our life, and that includes me," Madonna said (via Billboard). "I, too, go through challenging times in my life, and right now is one of them. Sometimes I think I can't do a show. I don't have the energy, I don't have the strength.”

The 57-year-old then paused to wipe a tear away from her face, before adding: "I come out here tonight and I can see your faces, and I look into your eyes and I see so much love and it gives me strength. So thank you. You are rebel hearts. I feel your hearts beating with mine.”

More: Guy Ritchie Hires Lawyer In Preparation For Custody Fight With Madonna

According to People magazine, Madonna and Ritchie are now gearing up for a custody battle over 15-year-old Rocco, who has reportedly refused to return home to the States, instead opting to stay in London with his father.

“She is going to fight, fight, fight, and she is going to fight to the end," a friend of the former couple told the magazine. "She is not happy. She is an excellent mother, and people can say whatever they want – but her children mean the world to her.”

More: Madonna And Guy Ritchie's Custody Battle Over Son Rocco Spills Over To Instagram

Rocco had been accompanying his mother on her ‘Rebel Heart’ tour, before visiting his father in December. However after he reportedly failed to return home for the holidays, Madonna took the matter to a Manhattan court, where a judge ordered Rocco to return to the US on December 23rd.

But despite the judge’s order Rocco has still not returned home and People reports that the former couple will be back in court for a second hearing February 3rd.