Archbishop Timothy Broglio said he was worried some members of the military could be put into situations where they are ordered to do something considered “morally questionable.”

Broglio, who also heads the US Conference of Catholic Bishops, told BBC News on Sunday that “it would be morally acceptable to disobey that order but that’s perhaps putting that individual in an untenable situation and that’s my concern.”

Broglio did not indicate what he considered a morally questionable order.

His comments come as President Donald Trump has sought to deploy troops onto the streets of US cities and threatens possible military action to take control of Greenland.

The Pentagon did not immediately respond to a request for comment.

Earlier this month, Trump told The New York Times he is constrained only by his “own morality.”

The archbishop expressed concern over Trump’s comments, suggesting that international law and one’s own moral principles should go hand in hand.

He said it does not seem reasonable for the US to attack and occupy Greenland, which is governed by Denmark, a Nato ally.

“It’d be one thing if the people of Greenland wanted to, wanted to be annexed, that would be one situation,” Broglio said. “But taking it by force when we already have treaties there that allow for a military installation in Greenland? It doesn’t seem necessary.”

Broglio is the latest leader of the Catholic Church to raise concerns about Trump’s demands. On Monday, three fellow archbishops decried the direction of US foreign policy. Church leaders have also pushed back on the Trump administration’s immigration agenda.

Six Democratic members of the US Congress in a video last year reminded members of the military that it was their duty to reject unlawful orders, drawing reproach from the Trump administration, including a Pentagon decision to demote Senator Mark Kelly of Arizona from his rank of retired Navy captain.