(CNN) Justin Bieber supports President Donald Trump's decision to help rapper A$AP Rocky, who is currently in the custody of Swedish police. But the "What Do You Mean" singer thinks others could benefit from the President's attention, too.

Bieber said on Twitter late Friday he appreciated the President lobbying Swedish authorities on behalf of the rapper. Earlier Trump had said his administration was working to resolve the matter

"I want my friend out," Bieber tweeted . "I appreciate you trying to help him. But while (you're) at it @realDonaldTrump can you also let those kids out of cages?"

I want my friend out.. I appreciate you trying to help him. But while your at it @realDonaldTrump can you also let those kids out of cages? — Justin Bieber (@justinbieber) July 20, 2019

Bieber was referencing the ongoing situation at the US-Mexico border, where some migrant children are being kept in detention centers.

Recent accounts from inside border facilities describe detainees being kept in crowded conditions without access to basic necessities like blankets, toothbrushes and soap.