All four members of Maine’s congressional delegation said Tuesday that they will wait to see the details of President Obama’s proposal before saying whether they would vote to authorize a military operation against Islamic State militants.

U.S. Sen. Angus King, an independent, said the limited version of Obama’s plan that he’s seen so far refers to using “not enduring defensive combat troops,” but he doesn’t know whether that means 180,000 troops on the ground for five years or a special forces team that could touch down to rescue a downed pilot.

“That’s a new term, so we don’t know exactly what that means,” King said. “There’s going to have to be some debate about what that term means.”

Republican U.S. Sen. Susan Collins, Democratic U.S. Rep. Chellie Pingree of the 1st District and Republican U.S. Rep. Bruce Poliquin of the 2nd District each issued a statement Tuesday saying they would wait to see specific language of Obama’s plan before deciding whether to back it.

Pingree added in her statement that she is “deeply skeptical of increasing the level of military involvement in the region.”

More than six months after the U.S. began conducting airstrikes against Islamic State forces in Iraq and Syria, the White House will ask Congress on Wednesday to approve a more defined campaign.

King said he has been calling on the administration since the airstrikes began to bring the question before Congress, the only branch of government that has the constitutional power to wage war. He said the military has so far been operating in a constitutional “gray area” since the president approved airstrikes under authority granted by Congress after the Sept. 11 terrorist attacks in 2001.

“I think the 2001 authorization for the use of military force has been interpreted very broadly. Now what we’re talking about, it’s not al-Qaida,” King said in a telephone interview. “I think the president is right to be coming to Congress, and I have been saying that for six months.”