They were removed from ventilators Saturday.
Doctors waited to upgrade the twins' condition until the girls spent 24 hours breathing on their own, hospital spokeswoman Laura Winder said.
The girls remain on heavy pain medication in the pediatric intensive care unit, the AP reports.
Winder said they have opened their eyes, but it's unclear how aware they are.
Russia has changed its position on the meeting of Russian President Vladimir Putin with his Ukrainian counterpart Volodymyr Zelensky