White House Chief of Staff Denis McDonough is denying claims that the administration threatened legal action against the families of kidnapped Americans if they paid ransom to their captors, the Islamic State.
McDonough hit a series of Sunday interview shows to promote the administration's counter-terrorism plan against the Islamic State, including a plea to Congress to fund anti-IS forces in Syria.
The families of James Foley and Steven Sotloff -- American journalists beheaded by the Islamic State -- said the government objected when they considered ransom payments, and even threatened prosecution.
"We didn't threaten anybody, but we made clear what the law is," McDonough said on Fox News Sunday. "That's our responsibility, to make sure we explain the law and uphold the law."
Ransom payments are prohibited under U.S. law, on the theory they would encourage terrorist groups to kidnap more Americans.
Read MoreHow ISIS earns $3M a day
McDonough said he sympathized with the Foley and Sotloff families, and noted that the administration attempted a hostage rescue in Syria.
"We took every effort -- and will continue to take every effort -- to secure people," he said.
In discussing the counter-terrorism plan, McDonough urged Congress to fund anti-IS fighters in Syria, and said the U.S. is "obviously" at war with the militant group.
The interviews aired a day after the Islamic State beheaded a third hostage, British aid worker David Haines
The plan that Obama announced Wednesday includes the prospect of U.S. airstrikes in Syria, while expanding ongoing strikes in neighboring Iraq.
Obama, McDonough, and other aides say the plan features assistance to local forces in Iraq and Syria to carry the fight against the Islamic State, also known as ISIL or ISIS.
In his round of interviews, McDonough echoed Obama's pledge to avoid using U.S. combat troops, and to rely on forces in Syria and Iraq.
"That's why the Syrian opposition is so important," McDonough said on CNN's State of the Union, later adding that "it's going to be Iraqi and other boots on the ground that are bringing this fight to ISIL."
On ABC's This Week, McDonough said that "what we want to make sure happens is that we have committed partners who can take the fight to ISIL on the ground. And they will have not only support from us from the air, but they'll also have training and equipment support from us."
Lawmakers and analysts have questioned Obama's plan, saying that the United States will have to get more involved -- including the prospect of ground troops -- if the Islamic State is to be defeated.