Madonna is in Haiti to visit humanitarian projects that ex-husband Sean Penn has been overseeing since the Caribbean nation's devastating earthquake in 2010, the actor said Monday.

Penn said in a brief phone call to The Associated Press that he had invited Madonna, with whom he has "maintained a great friendship over the years," to visit several times and that she had come with her son Rocco. He said they arrived a "couple of days" ago, and he wasn't sure when she would leave.

"She's here, she's seeing, she's made the effort to come here, and I'm thrilled by that," Penn said, adding that he hoped Haiti might inspire her to seek out a cause in the country. "She has a unique platform, and wherever she chooses to bring that to, it's very well."

Madonna's been busy posting photos on Instagram. One shows her posing with others at a new hospital built by public health pioneer Dr. Paul Farmer in the central part of the country. The caption: "Revolution of Love in Haiti." Another picture shows a view of the mountains at dusk. The caption: "Sunset in Haiti. This is Heaven!"

abcnews