Vatican City. Pope Francis on Sunday told soldiers, police and other law enforcement officials from around the world that armed force can only be used for legitimate defense and must always respect international law.

The pontiff reappeared in public for the first time since he was diagnosed with bronchitis on Thursday to celebrate an outdoor Jubilee Mass for the armed forces, police and security personnel. However, after a few words, he handed off his homily to an aide to read, saying he was having difficulty with his breath.

“I would like to recall the teaching of the Church in this regard: The Second Vatican Council says that those who exercise their profession in the ranks of the army in the service of their homeland should consider themselves as servants of the security and freedom of their people,” Francis said in his final prayer.

“This armed service must be exercised only for legitimate defense, never to impose dominion over other nations, and always observing international conventions regarding conflicts,” he added.

The pontiff launched a new appeal for peace, citing conflicts around the world, including Ukraine, the Middle East, Myanmar and Sudan.

“Let the weapons be silenced everywhere and let the cry of the people asking for peace be heard,” Francis said.

Since being diagnosed with bronchitis on Thursday, the pope had continued his activities and audiences indoors at Casa Santa Marta, the Vatican residence where he lives, until Sunday.

Francis has long battled health problems including long bouts of bronchitis. He uses a walker or cane when moving around his apartment and recently fell twice, hurting his arm and chin.

Speculation about the pope's health is a constant in Vatican circles, especially after Pope Benedict XVI broke 600 years of tradition and resigned from the papacy in 2013.

Francis has said that he has no plans to resign anytime soon, even if Benedict “opened the door” to the possibility. In his autobiography “Hope” released this month, Francis said that he hadn’t considered resigning even when he had major intestinal surgery.