President Obama speaks during his press conference at the G20 Summit in Antalya, Turkey, on Monday. (Tolga Bozoglu/EPA)

President Obama complained Monday that Republicans’ proposals on what to do about the Islamic State terror group are largely the same things he’s already doing.

For the most part, he’s right. The United States has long been conducting airstrikes, sending military advisers to the region and working to broaden an international coalition against the group.

But Republican presidential candidates want even more of these things — although they decline to offer many specifics. Some also advocate enforcing a no-fly zone over Syria, and a handful favor sending more U.S. troops.

Obama has rejected calls for a no-fly zone and on Monday dismissed talk of deploying tens of thousands of combat troops into Syria.

Republican presidential candidate and former Florida Gov. Jeb Bush speaks during the Sunshine Summit conference in Orlando on Friday. (Joe Raedle/Getty Images)

Speaking with reporters in Turkey, he said that his approach to countering Islamic State “is the strategy that ultimately is going to work.” Obama sharply criticized Republican critics for not offering a detailed strategy that is different from his, beyond calling for additional ground troops.

“Some of them seem to think that, if I was just more bellicose in expressing what we’re doing, that that would make a difference. Because that seems to be the only thing that they’re doing, is talking as if they’re tough.”

In recent days, GOP front-runner Donald Trump has revived his calls to “bomb the s---” out of oil fields controlled by Islamic State but has been unclear on how many troops he would deploy to the region. Sen. Marco Rubio (R-Fla.) wants NATO to invoke Article 5 of its charter — that an attack on one member country is an attack on all that must be met with a military response. Former Florida Gov. Jeb Bush wants the U.S. to “declare war” on Islamic State and Syrian President Bashar al-Assad.

Asked Monday to name the first, second and third things he would do as president to defeat the Islamic State, Trump didn’t directly answer, saying instead on MSNBC that he would have bombed terrorist training camps “a long time ago.” He focused instead on criticizing Obama for avoiding use of the phrase “radical Islam.”

Later in the interview, Trump said he was willing to send 10,000 U.S. troops to the Middle East to fight the Islamic State, but added: “I’d engage other countries.”

When asked whether he would be prepared to deploy “large numbers” of U.S. military forces to defeat ISIS, Trump said: “No, I’m not. I would put some there, but I’m not.”

Republican presidential candidate Donald Trump speaks during a rally last Thursday at Iowa Central Community College in Fort Dodge, Iowa. (Charlie Neibergall/AP)

Some Republicans are openly criticizing their own field for failing to offer a substantive counterargument at a moment of potential weakness for Obama and Democratic front-runner Hillary Rodham Clinton.

Steve Schmidt, a top strategist on the campaigns of George W. Bush and John McCain, called Obama’s Syria strategy a “disaster,” but he said that he has yet to see any Republican seize the opportunity to present a clear contrast.

“Republicans will have a structural advantage on national security in the next election,” Schmidt said. “But none of the candidates have thus far risen to the occasion and talked directly and clearly to the American people about why we need to destroy this enemy, what will be required to do it and the sacrifice that will be required.”

Ron Bonjean, a Republican strategist currently not working for any presidential candidate, said that candidates who “have a serious working foreign policy knowledge will quickly rise above those don’t.”

“The status of being an outsider during a growing crisis like this could soon diminish if ISIS attacks continue to spread,” he said, using a common acronym for the terrorist group. “This would favor Jeb Bush, Marco Rubio, Ted Cruz and Lindsey Graham.”

Bonjean said retired neurosurgeon Ben Carson is most at risk in the new foreign policy debate because “he seems entirely lost during interviews and lacks serious depth of how the world works.” Schmidt agreed, saying that Carson has spewed out “gibberish” and “maximum incoherence” in recent days when discussing foreign affairs.

Carson took heat after the fourth Republican debate for appearing to suggest inaccurately that China has a military presence in Syria. He repeated those assertions again during an interview on “Fox News Sunday.”

In the interview, Carson struggled to attach specifics to his plan to defeat the Islamic State. Among other things, he could not name a specific country or leader he would call to assemble an international coalition to counter the terror group.

“My point being that if we get out there and we really lead and it appears that we’re making progress, that all of the Arab states and even the non-Arab states who are, I think, beginning to recognize that the jihad movement is global” will join, Carson said.

Rubio, a hawkish Republican who is seeking to separate himself from the pack by demonstrating a superior command of foreign policy, supports creating a no-fly zone over Syria — a move backed by most GOP candidates and by Clinton. In the wake of the Paris attacks, Rubio also called for invoking NATO’s charter, but France has declined to press the provision.

When it came to troop levels in Syria, Rubio called Obama’s decision to send special operations advisers into the country “an important start” in an interview with CBS News this month. On Monday, he said at the Wall Street Journal CEO Council annual meeting that sending 50 advisers was “insufficient,” but he declined to say how many would be enough. “Ultimately, the numbers need to be set by the tacticians,” he said.

Bush first outlined his ideas on defeating the Islamic State in August and has been repeating them in recent television appearances.

On NBC’s “Meet the Press,” Bush said that Obama should “declare a no-fly zone over Syria. Directly arm the Peshmerga forces in Iraq. Re-engage with the Sunni tribal leaders. Embed with the Iraqi military. Be able to create safe zones in Syria. Garner the support of our European allies and the tradition Arab states. Lead. That’s what I want him to do. I want him to lead.”

Among Republican presidential candidates, only Sen. Rand Paul (R-Ky.) has expressed any caution when it comes new military action. On Monday, he said troops shouldn’t be deployed without new congresisonal authorization.

“The constitution’s pretty clear on this. We’d need a new authorization,” he said. “I also believe that if there’s ever to be a long-lasting victory that civilized Islam is going to have to stand up. In order for there to be a long-lasting victory, radical Islam will not be stamped out by Americans or Christians or French for that matter.”

Juliet Eilperin and David Weigel contributed to this report.