The Obama administration tried to up the ante on Wednesday by promising non-lethal military aid to Ukraine, but it did little to satisfy the rising congressional demands to send weapons and other heavy military equipment. Both Carter and Joint Chiefs of Staff Chairman Gen. Martin Dempsey have broken with the president and could support arms to Ukraine.

And now many lawmakers, including some influential Democrats, are pushing for arms for Ukraine.

“Providing nonlethal equipment like night vision goggles is all well and good, but giving the Ukrainians the ability to see Russians coming but not the weapons to stop them is not the answer,” Sen. Robert Menendez of New Jersey, the top Democrat on the Senate Foreign Relations Committee, declared Tuesday during a committee hearing on the issue.

The White House said Wednesday it was providing Ukraine $75 million in non-lethal aid that included surveillance drones, radios and other light equipment, as well as transferring 30 armored Humvees and up to 200 unarmored ones. And Secretary of State John Kerry also announced that new sanctions were being enacted by the Treasury Department.

Yet Dempsey has told the Senate Armed Services Committee that he would “absolutely consider providing lethal aid” to Ukraine, while Carter said at his confirmation hearing he was “very much inclined in that direction.”

The disagreement between the White House and the Pentagon over strategy in a volatile region represents a rare public dispute within President Barack Obama’s Cabinet — and shows that Carter, just confirmed as defense secretary, can be more willing than his predecessors to air his differences with the president.

On Tuesday, before the Senate Foreign Relations Committee, Victoria Nuland, the assistant secretary of state for European affairs, acknowledged a “spirited debate” on the issue within the administration, as well as among countries.

Congress, on the other hand, has argued with a largely unified voice that Ukraine needs U.S. weapons to balance the military playing field and deter Russia from getting further involved militarily in eastern Ukraine.

“This aid will be completely ineffective,” House Speaker John Boehner spokesman Cory Fritz said of Wednesday’s aid package. “The Ukrainians are begging for help, and the Congress is begging the administration to provide the defensive lethal assistance we authorized in December. Our allies deserve better.”

The speaker wrote the president last week, urging Obama to approve “the transfer of lethal, defensive weapons systems to the Ukrainian military.” The letter from the Ohio Republican was notable not just because it had senior GOP leaders and committee chairmen signed on, but also the top Democrats on the Foreign Affairs, Armed Services and Intelligence Committees.

“I don’t see this changing the thinking up here on any side of the aisle,” a House committee aide said of the administration’s new non-lethal aid announcement. “It doesn’t go nearly far enough.”

Lawmakers say they’re particularly concerned by comments from German Ambassador to the U.S. Peter Wittig, who told The Associated Press that Obama had agreed to hold off on providing weapons in a meeting last month with German Chancellor Angela Merkel.

“The fact that it appears that the president may have made a commitment to Angela Merkel while she was here, or the German ambassador, to not do that certainly has created a lot of concern on both sides of the aisle,” Senate Foreign Relations Chairman Bob Corker (R-Tenn.) said Wednesday. “What Secretary Kerry said today is welcome, but we know we need to do far more to be successful.”

The bipartisan congressional frustration was on full display in Corker’s committee on Tuesday, when senator after senator complained at a hearing that the administration hadn’t acted on arming the Ukrainians.

“I guess when all of this is solidified, then it will be too late,” Menendez said.

“I don’t buy this argument that, you know, us supplying the Ukrainians with defensive weapons is going to provoke Putin,” said Sen. Chris Murphy (D-Conn.).

Nuland emphasized the administration has provided $355 million in foreign assistance to Ukraine and the president’s fiscal 2016 budget includes an additional $514 million.

She said that the second Minsk agreement, struck last month between Russia, Ukraine, France and Germany, had seen some removal of Russian separatist heavy weapons, but acknowledged that transfers of Russian tanks and other equipment have occurred over the border to eastern Ukraine.

“If we can see these Minsk agreements implemented, if we can see peace in eastern Ukraine, that offers the best hope for the Ukrainian people. But we will continue to evaluate the situation,” Nuland said.

Democrats were nevertheless more supportive of the latest administration move, with Senate Minority Whip Dick Durbin of Illinois calling the new equipment a “timely increase of U.S. military aid.”

“I applaud President Obama for sending a strong signal both to the people of Ukraine as well as to the Kremlin,” Durbin said in a statement. “But more can and must be done for Ukraine, including defensive weapons as soon as possible.”

In December, Congress approved the Ukraine Freedom Support Act, which authorized up to $350 million in defensive weapons to Ukraine. But the administration has not used that authority, which has prompted lawmakers to consider additional legislation to press the issue.

Last month, House Armed Services Chairman Mac Thornberry (R-Texas) and ranking member Adam Smith (D-Wash.) unveiled a bill to provide $1 billion annually in defensive weapons to Ukraine. And Rep. Eliot Engel of New York, the top Democrat on the Foreign Affairs Committee, is drafting legislation he plans to introduce soon to ramp up Ukraine aid.

A group of 13 senators is eyeing the appropriations process to provide weapons for Ukraine. The group, led by Sen. Kelly Ayotte (R-N.H.), sent a letter Tuesday to Appropriations leaders, urging them to include funding for Ukrainian weapons that was authorized in the December legislation.

The annual defense authorization bill — one of the few so-called must-pass pieces of legislation — is also being eyed as a possible vehicle for pushing military aid to Ukraine.

Still, any of the legislative options could take months to enact, if at all, which means that convincing the president to sign off on arms to Ukraine remains the best option for those pushing it.

“Passing legislation is always an uphill battle,” the aide said. “[But] Congress is not happy where American policy is on this, and that’s bicameral and bipartisan.”

Austin Wright contributed to this report.