The hesitation comes as a bipartisan majority in the
"I'm pleased that
In a further sign of a measured approach, Gen.
"If we can restore the border, it goes a long way to putting pressure on [Islamic State] that will lead to its ultimate defeat," Dempsey told reporters traveling with him in Paris. He called the border a "sieve."
The approach highlights growing questions about the administration's still-evolving strategy against the Sunni extremists who have overrun about a third of Syria and Iraq. But Hagel defended the plan to support Iraq's army and Kurdish forces and slowly build up a separate proxy force in Syria to take on the militants there.
"We recognize this is difficult, we recognize there is no good option here," Hagel told the House Armed Services Committee. "There will always be risks … but we believe that risk is justified given the threat."
Hagel told the committee that a bombing plan for Syria was approved by his office, by the
Hagel said the plan calls for targeting Islamic State strongholds in northeastern Syria, including its command-and-control networks, logistics capabilities and infrastructure. He said the president "has not yet approved its finality," but did not say whether Obama had sought revisions or a delay.
"What I can tell you is that the president was pleased to have the opportunity to review the hard work that's been underway at the Pentagon for quite some time and to consider those detailed plans that were put forward before him. And he was pleased with their work," Earnest said. "But their work is ongoing and continues."
U.S. intelligence believes about two-thirds of the estimated 31,000 Islamic State militants operate in Syria, where they have largely supplanted other groups seeking to topple President
Although the White House has urged Assad to give up power, it does not want to be dragged into the country's bitter civil war, which has left more than 190,000 people dead since 2011.
Administration officials, who are scrambling to assemble an international coalition against Islamic State, have said it won't involve an American-led bombing campaign, referring to the start of the 2003 invasion of Iraq. They are hoping to enlist Arab nations to conduct at least some of the airstrikes.
U.S. warplanes and drones have conducted 176 airstrikes against Islamic State positions and convoys in Iraq since Aug. 8 but have not attacked the militants across the border in Syria.
Dempsey caused a stir this week when he repeatedly warned a Senate Armed Services Committee hearing that U.S. ground troops ultimately may be needed to assist Iraqi and Kurdish forces during major battles in Iraq, saying Obama had told him he would consider such requests "on a case-by-case basis."
Dempsey's spokesman later said he was referring to the possibility that small numbers of U.S. advisors might be needed to accompany Iraqi and Kurdish forces in combat, not large number of ground troops.
Dempsey told the committee it would take three to five months to recruit and screen Syrian fighters for extremist ties, and eight to 12 months to prepare them for battle. He said they would require independent Syrian commanders, not Americans, and that he hoped special operations troops from Jordan or another Arab state would assist them.
The training will occur in Saudi Arabia and another Arab nation, reportedly Qatar. The fighters will be provided with light arms and undergo about eight weeks of training on infantry tactics, calling in mortar fire, using radios and other basic soldier skills, officials said.
Dempsey did not say whether the rebels would be given antitank weapons capable of penetrating armored vehicles, which Islamic State forces have captured. But he said their weapons would "overmatch" the militants and could include "higher end equipment" over time.
"As we get to know these people, not only their skills … but once we know what's in their hearts, I think we may have the opportunity to adapt the kind of equipment we provide," he said Thursday.
Pentagon officials have recommended that Obama approve airstrikes in Syria in coming months to inflict damage on militant forces until the proposed rebel force is ready to launch ground attacks on them.
For now, it's far from clear who within the badly fractured Syrian opposition will control it, how effective it will be against hardened Islamic State fighters armed with heavy weapons and armored vehicles, and how the rebels will coordinate with the U.S. if it does launch airstrikes.
"This is not building a little 10- to 12-man squad to go and conduct guerrilla tactics or go defend your village," Dempsey said. "This is about working with them to a point where they have leaders who can maneuver a couple hundred of these opposition groups at a time. That just takes a little time."
A bigger concern is who controls them. The rebels should not be under direct U.S. command, he said, because once Pentagon assistance to the rebels ends, there would be no way to control them. He said they need to be under the control of civilian leaders from the Syrian opposition.
"We really need to have a clearer understanding" about whom in Syria the rebel force will be accountable to, Dempsey said. "What we don't want to do is build a force that is accountable to us."
Islamic State released a video that appears to show a captive British journalist, identified as John Cantlie. He wears an orange jumpsuit like those worn by two American journalists and a British aid worker who were beheaded by Islamic State, but the video does not include any violence or show any militants.
The clip, titled "Lend Me Your Ears," opens with the journalist looking directly at the camera. Cantlie says he feels "abandoned" by his government, and that he will show the "motivation of the Islamic State and how the Western media, the very organization [he] used to work for, can twist and manipulate the truth to the public back home."
Along with a Dutch colleague, the experienced war correspondent and photographer escaped a kidnapping in 2012 by militants in Syria. But Cantlie later returned to Syria, according to British press accounts, and was captured.