NATO’s top commander bluntly told the Pentagon on Wednesday that the allied effort to slow Russia’s advance in Ukraine isn’t working. He delivered that message as the Obama administration appeared to back away from earlier indications that the U.S. would arm the Ukrainian army against pro-Putin forces.

“Right now we are not arming the Ukrainians with lethal weapons, and what we see is that Russians continue to provide their force, continues to build the capability,” Air Force Gen. Philip Breedlove, the supreme allied commander of NATO and commander of U.S. European Command, told reporters at the Pentagon on Wednesday after testifying before the House Armed Services Committee hours earlier.

A decision to provide that lethal aid “could cause positive results, could cause negative results,” he added. “But what we’re doing now is not changing the results on the ground.”

Breedlove, however, said he was ready with plans for the U.S. to provide military assistance to a beleaguered Ukrainian Army fending off Russian backed rebels—should the Obama administration ever make a decision.

The U.S. has conducted comprehensive studies of Ukrainian military needs, he added, and has a good sense of what it could provide to assist with an effective defense with Russian troops in the east.

Breedlove—once an advocate for a stronger U.S. stance in the Ukraine conflict—painted a bleak picture of a Russia increasingly intervening in the war there, as the West debates whether to help.

“It’s getting worse everyday,” Breedlove told reporters. “We have seen a steady escalation.”

Meanwhile, the Kremlin’s involvement in the conflict had evolved from opaque to direct, Breedlove said. The commander added that Russia had sent “well over” 1,000 combat vehicles.

Breedlove also said Wednesday he could not say “what’s going on in Mr. Putin’s head,” but that Putin’s goal “is to keep Ukraine out of the West and the West out of Ukraine.”

Advocates for arming Ukraine are growing increasingly aghast at the passing time without lethal aid from the United States.

“It’s disappointing that it still hasn’t occurred,” Sen. Bob Corker, the chairman of the Senate Foreign Relations Committee, told The Daily Beast. “[The Obama administration has] put the decision off. We’ve pressed them in Congress, we’ve passed legislation. It passed unanimously on the Senate floor to authorize them to [provide lethal defensive arms to the Ukrainians].”

Supporters of providing such weapons argue Ukraine cannot defend itself otherwise and Russian aggression cannot go unanswered.

“The West is endangering their own interests by taking so long. If Ukraine is forced to capitulate to Putin’s agenda, then all of those worst fears that the West has will begin to materialize because based on the rhetoric and everything that we hear coming from the Russian state, Ukraine is not the end. Ukraine is just the beginning,” Pavel Yarmolenko, a spokesman for the Ukraine Freedom Support Group, told The Daily Beast.

But there are risks—serious risks—to providing those arms. House Armed Services Committee Chairman Mac Thornberry acknowledged that it was impossible to know how Putin might react if the United States were to provide more lethal aid to Ukraine, but retorted that the world has seen “how he has responded without us providing weapons, and that isn’t going very well.”

Breedlove stopped short of advocating for lethal defensive weapons as some has urged in the last few weeks. The administration now appears to have moved away from such a decision in the face of vehement opposition from the U.S.’s NATO partners. Instead, he called the military part of a multifaceted arsenal that includes diplomatic and economic efforts.

“This will not end militarily,” the supreme allied commander told reporters. But Breedlove did not describe his own personal opinion on the issue of lethal aid.

“Gen. Breedlove has supplied his best military advice to the chain of command on options so that Administration can make their decision. To openly discuss his [position] jeopardizes his best advice and our role to inform our leaders on what we assess to be options,” Captain Gregory Hicks, a spokesman for the general, told The Daily Beast.

Earlier this month, the administration appeared to move toward providing Ukraine such weapons, which it had repeatedly until Germany and France led a Europe push for a ceasefire agreement in Minsk. Within hours of its implementation, the agreement collapsed.

Opponents charge that such weapons will not be enough for Ukraine to fend off Russia, potentially forcing another weapons escalation and eventually a proxy war.

Under Secretary of Defense for Policy Christine Wormuth outlined these concerns at the hearing Wednesday, suggesting that Russia could “double down” if the United States were to ramp up military aid to Ukraine. The result, she said, could be “more human suffering,” meaning that tools such as economic sanctions could be “potentially more effective.”