Lady Gaga says marijuana has been a "spiritual experience" for her.

The singer is on her Born This Way Ball tour at the moment and performed in Amsterdam on Monday and Tuesday. Using the drug has effectively been decriminalised in the country, which Gaga marked by lighting up a cigarette apparently containing the substance while on stage.

"I want you to know it has totally changed my life and I've really cut down on drinking. It has been a totally spiritual experience for me with my music," she is quoted as saying by British newspaper The Sun.

Gaga jokingly claimed she was considering talking to US President Barack Obama to see if the drug could be legalised globally.

She lectured on the "medical wonders" of cannabis and said the picture of a leaf synonymous with the drug is the "new peace sign".

"It's like saying everybody needs to take a breath and it's going to be OK," she reportedly said.

Although she advises her fans to be loving, Gaga hasn't always had things easy. She has been involved in a public feud with Madonna, after the Queen of Pop reportedly thought Gaga's song Born This Way sounded like her track Express Yourself.

Much has been made of the difficult relationship between the pair, but Madonna took steps to mend it on Saturday while on stage in Atlantic City. She dedicated her track Masterpiece to the younger singer and hinted she is ready to put their bad blood behind her.

"You wanna know something? I love her. I love her. I do love her. Imitation is the highest form of flattery," she said.

"One day, very soon, we're going to be on stage together. Just you wait. You think I'm kidding? I love Lady Gaga."