According to a Vatican statement, Pope Emeritus Benedict XVI’s health has deteriorated due to his age, and doctors continually evaluate his condition.

After requesting the faithful to pray for Benedict earlier in the day, Pope Francis visited him at the monastery on Vatican grounds, where he has lived since his retirement in 2013.

“Concerning the health problems of the emeritus pope, for whom Pope Francis asked for prayers at the close of his general audience this morning, I can report that a worsening owing to advanced age has occurred in the recent hours,” said Vatican spokesman Matteo Bruni.

“At the moment, the issue is under control and is being closely monitored by doctors.”

Pope Francis deviated from his scheduled statements at the close of his Wednesday session with the public in a Vatican auditorium to claim Benedict is “very unwell” and begged the faithful to pray for the retired pontiff. Francis did not go into detail on Benedict’s illness. “I’d like to encourage everyone to pray for Emeritus Pope Benedict, who is quietly supporting the church,” Francis stated.

“I’d want to remind you that he’s unwell. Let us pray to the Lord to comfort and maintain him in his witness of love to the church till the end.”

Benedict, the first pontiff to resign in 600 years, has grown feeble recently as he has committed his post-papacy life to prayer and meditation. Archbishop Georg Gaenswein, his longtime secretary, noted that while he was physically feeble, he was nonetheless lucid when he turned 95 in April. Pope Francis paid a previously announced visit to Benedict at the monastery four months ago, accompanied by new cardinals.

A snapshot from the period shows a skinny Benedict clasping Pope Francis’ hand and smiling at each other.

Benedict attended a couple of cardinal-elevation ceremonies in St. Peter’s Basilica during his first years of retirement. However, in recent years, he has not been physically able to attend these lengthy services. Pope Paul VI promoted him to cardinal in 1977, and he served as the Vatican’s doctrinal watchdog as Cardinal Joseph Ratzinger before being elected pontiff in 2005.

Some traditionalists were disappointed by Benedict’s decision to quit in 2013, but Francis welcomed it as a courageous admission that bodily weakness prohibited him from properly serving the world’s 1. 3 billion Catholics.

Francis disclosed in an interview with the Spanish daily ABC earlier this month that shortly after being elected Pope, he composed a resignation letter in case medical problems prevented him from carrying out his duties. He has a history of health problems, including a knee ligament problem that necessitated using a wheelchair or a cane. However, in the interview, he downplayed the challenge, noting that “one governs with the head, not the knee.” Limburg Bishop Georg Baetzing, the chairman of Germany’s bishops’ conference, also endorsed Pope Francis’ plea for prayers for Benedict.

“My thoughts are with Pope Emeritus Benedict XVI,” Baetzing stated. “I pray for him, asking the Lord for strength and peace.”