Pope Francis' condition remains "critical," the Vatican said Sunday, noting that he has not experienced further respiratory issues.

In a statement, the Vatican confirmed that the Pope received two units of concentrated red blood cells, which had a beneficial effect and led to an increase in his hemoglobin levels.

While thrombocytopenia remains stable, some early signs of renal insufficiency have appeared, though they are being actively managed, the statement added.

The 87-year-old pontiff continues to receive high-flow oxygen therapy via nasal cannulas but remains alert and oriented, according to the Vatican.

Given the complexity of his condition and the time needed for treatments to take effect, the prognosis remains cautious, Vatican said.

Vatican said Pope Francis attended Holy Mass in his apartment on the tenth floor of the hospital, joined by those overseeing his care.