Republican presidential candidate Donald Trump backed down Friday from claims that he would order the U.S. military to waterboard militants and carry out other acts that violate international law, as the top general in the U.S. military was asked to weigh in on Trump’s previous remarks.

Trump, the Republican front-runner, has said repeatedly that he wants to waterboard suspected terrorists, kill the family members of those who carry out terrorism and commit other acts that would leave U.S. troops with a quandary if Trump is elected: Do they follow the orders of their commander in chief, or the Uniform Code of Military Justice that governs their actions?

In a letter Friday, Sen. Lindsey Graham (R.-S.C.), a frequent critic of Trump’s who withdrew from the Republican presidential race earlier this year, asked Marine Gen. Joseph F. Dunford, chairman of the Joint Chiefs of Staff, to weigh in on the issue.

Graham did not mention Trump by name. But he asked the general for his opinion on intentionally targeting the family members of terrorists, whether waterboarding and “other extreme interrogation techniques” are authorized and legal in the military, whether he would view orders to target children and other noncombatants as lawful, and what advice he would offer to service members who were issued such orders.

“One of the things I most admire about you is that your warrior spirit coexists with an ethical underpinning,” Graham wrote Dunford. “It makes you, and all who serve in the armed forces, the finest fighting force the world has known.”

Dunford could not immediately be reached for comment.

In a statement Friday, Trump clarified that he would not order a military officer to disobey the law. If elected, he said, he will be bound by laws “just like all Americans” and will meet those responsibilities. He added that he feels very strongly about the need to attack and kill terrorists who target the United States and its people, and will not forget the attacks of Sept. 11, 2001.

“I will use every legal power that I have to stop these terrorist enemies,” Trump said. “I do, however, understand that the United States is bound by laws and treaties and I will not order our military or other officials to violate those laws and will seek their advice on such matters.”

Trump has made regular references to waterboarding on the campaign trail, assuring his supporters that the would reinstate the practice, along with other “tougher” interrogation techniques. He has been steadfast in his belief that those techniques are highly effective and has dismissed concerns about their legality under international law.

Trump was adamant on the matter Thursday night during the 11th GOP debate, when moderator Bret Baier pressed on what he would do if U.S. service members refused to comply with his orders.

“They won’t refuse. They’re not going to refuse me, believe me,” he said. “If I say do it, they’re going to do it. That’s what leadership is all about.”

Trump also sought to draw a sharp distinction between himself and Sen. Ted Cruz (R.-Tex.), whom he accused of weakening on the issue in a February debate. He made clear that he believed neither waterboarding nor pursuing the families of suspect terrorists was beyond the pale.

“It’s fine, and if we want to go stronger, I’d go stronger, too, because frankly that’s the way I feel,” Trump said. “Can you imagine, can you imagine these people, these animals over in the Middle East that chop off heads sitting around talking and seeing that we’re having a hard problem with waterboarding?”

“We should go for waterboarding and we should go tougher than waterboarding,” he added.

The issue would have been complicated for rank-and-file members of the military, said James Weirick, a retired Marine lieutenant colonel and military lawyer. Any service member who disobeys an order that he deems unlawful bears the burden of proving that, he said.

Weirick said that Trump has only made “bumper-sticker statements” regarding the killing of terrorists’ families, leaving some gray area in how to interpret his remarks. For example, if a family member was killed while detained by the U.S. military, that would violate the law of armed conflict, Weirick said. However, if a terrorist’s family was killed along with him in an airstrike on his home, that could be deemed acceptable collateral damage or reasonable if they provided material support to the terrorist, he added.

The rhetoric of the Republican presidential race has put senior military officers, who are not supposed to take political stands, in the awkward position of being asked to comment on remarks made on the campaign trail. In another example, the top U.S. general last month said that “carpet-bombing” the Islamic State militant group was not a good idea because the military does not indiscriminately bomb areas with civilians.

Army Lt. Gen. Sean MacFarland weighed in on that debate during a briefing with Pentagon reporters in response to a question after Cruz said that if he was elected, he would target the Islamic State and “carpet-bomb them into oblivion.”

Responded MacFarland: “We’re the United States of America, and we have a set of guiding principles and those affect the way we as professional soldiers, airmen, sailors, Marines, conduct ourselves on the battlefield. So indiscriminate bombing, where we don’t care if we’re killing innocents or combatants, is just inconsistent with our values. And it’s what the Russians have been accused of doing in parts of northwest Syria. Right now we have the moral high ground, and I think that’s where we need to stay.”

Thomas Gibbons-Neff contributed to this report.