President Obama has decided not to directly confront Russia over its new air offensive in Syria, believing that President Vladi­mir Putin will soon find himself in a Syrian “quagmire,” but he has approved a new escalation of U.S. efforts against the Islamic State.

Obama laid out the U.S. response to Russia’s actions during a meeting with senior aides Thursday evening. Details were firmed up in a meeting Friday morning among national security principals at the White House, senior administration officials said.

At the same time, the president also approved proposals, made prior to this week’s Russian actions, to strengthen the U.S. fight against the militants. Those measures were recommended by Obama’s new Joint Chiefs of Staff chairman, Gen. Joseph F. Dunford Jr.

They include direct U.S. weapons shipments, overland from Iraq, to Syrian Kurdish and Arab fighters who in recent months have pushed the Islamic State from a major portion of northern Syria along the Turkish border.

The Kurds are now expected to begin moving south toward Raqqa, the de facto militant capital, in north-central Syria.

U.S. airstrikes are also slated to increase west of the Euphrates, where U.S.-backed opposition forces have had little recent success against the Islamic State. Those strikes are being launched from Incirlik air base in Turkey, where aircraft from other coalition partners will join U.S. planes.

Far from attacking the Islamic State, as Russia has said it intends, its three days of airstrikes appear to have focused largely on opposition forces, some of them U.S.-backed, that are fighting across western Syria against the army of President Bashar al-
Assad, whose government is backed by Moscow.

Obama did not respond directly to questions about what, if anything, he would do to help the embattled opposition, which includes thousands of fighters who have been trained and armed over the years by the CIA, as well as non-Islamic State extremists. Senior administration officials said that training and limited supplies for those inside Syria would continue but that the policy was likely to continue.

Current and former U.S. officials voiced concern that the Russian bombing would damage a covert program already struggling to gain traction in the fight against Assad. It is also likely to increase frustration among the rebels “that the Americans don’t do as much as the Russians do for their side of the conflict,” said Robert Ford, the former U.S. ambassador to Syria who resigned that position in part out of frustration with administration policy.

Rep. Adam Schiff (Calif.), the ranking Democrat on the House Intelligence Committee, said the Russian move “really ups the ante for the United States. We do have great reputational costs in letting the Russians assert themselves and be seen as a more forceful actor on the ground in Syria. We also have a deep interest in protecting the moderate population, and that’s going to push us to have greater involvement, which is a risky proposition.”

Any direct military response against Russia, a U.S. military official said, would probably require new presidential authorities. But Obama, speaking at a White House news conference Friday, made it clear that he has no intention of directly confronting Russian forces.

“We’re not going to make Syria into a proxy war between the United States and Russia. That would be a bad strategy on our part,” Obama said. “This is a battle between Russia, Iran and Assad against the overwhelming majority of the Syrian people. Our battle is with ISIL,” he said, referring to the Islamic State.