Pope Francis has decried the naming of the 'mother of all bombs', the US military explosive Trump used to bomb Afghanistan in April. He said the word 'mother' should not be used to describe a weapon.
Speaking with students at the Vatican on Saturday, the pontiff said he was 'ashamed' when he heard the name, according to the Catholic Herald.
'A mother gives life and this one gives death, and we call this device a mother. What is going on?' he said.
The GBU-43 Massive Ordnance Air Blast (MOAB) is the US military's largest non-nuclear weapon ever deployed in combat, hence its nickname. The explosive weighs in at 21,600lb (9,800kg), contains 11 tons of explosives and has a blast radius of one mile.
The weapon was launched in April by President Trump in a targeted attack that killed at least 36 ISIS militants.
The MOAB is a GPS-guided munition that had never before been used in combat since its first test in 2003, when it produced a mushroom cloud visible from 20 miles (32 km) away.
President Trump is set to meet Pope Francis for the first time at the Vatican on 24 May.
Trump and Francis already have some tense history. During the presidential campaign, Pope Francis said of Trump: 'A person who thinks only about building walls, wherever they may be, and not building bridges, is not Christian. This is not the gospel.'
Trump, who had once said that Francis 'seems like a pretty good guy', called the Pope's disparaging of his faith 'disgraceful'. He warned him: 'If and when the Vatican is attacked by ISIS...I can promise you that the Pope would have only wished and prayed that Donald Trump would have been President because this would not have happened.'
After Trump's election, Pope Francis said that he would 'wait and see' how Trump acts as President before judging him, but simultaneously warned of the threat of populist authoritarian figures.