WASHINGTON (AP) — The Obama administration is taking a wary, wait-and-see approach toward the new Ukraine peace agreement, which was reached without direct American input and as the U.S. considers whether to give defensive weapons to Ukraine and slap fresh sanctions on Russia.

Despite reservations about the agreement, U.S. officials say any action on lethal aid or new sanctions is on hold at least for the moment.

While welcoming the deal in principle, the administration is concerned that the compromise — struck on Thursday after 16 hours of negotiations in Minsk among the leaders of France, Germany, Russia and Ukraine — may give too much to Russia and the pro-Russian rebels. U.S. officials are highly skeptical that either the rebels or Russia will abide by the pact, which lays out a series of phased steps for Ukraine and the separatists to take, starting with a cease-fire to begin on Sunday.

That skepticism was evident in notably cautious statements about the agreement issued by the White House, which described it as a "potentially significant step," and Secretary of State John Kerry, who noted that there is "a long road ahead before achieving peace and the full restoration of Ukraine's sovereignty."

"This agreement must now be followed by immediate, concrete steps to fulfill the commitments by all parties," White House press secretary Josh Earnest said. "The true test of today's accord will be in its full and unambiguous implementation, including the durable end of hostilities and the restoration of Ukrainian control over its border with Russia."

"Actions will be what matter now," Kerry said. "We will judge the commitment of Russia and the separatists by their actions, not their words."

Should Russia and the rebels not comply, U.S. officials say they are ready to raise the costs for Moscow with additional sanctions and, as fighting intensified in recent weeks, publicly floated the idea of sending defensive weapons to help Kiev defend itself. News that the White House was reconsidering its previous opposition to arms transfers was followed in quick successions by a flurry of European and Russian diplomatic activity that led to the Minsk meeting.

Though they may have played a part in spurring the diplomacy, the threat of potential weapons transfers and new, tougher sanctions has been pushed to the back burner. Decisions on them will wait until there is an assessment of the results of the Minsk deal, the officials said.

"We maintain the ability and the resources to put additional sanctions in place, should the situation on the ground warrant it," State Department spokeswoman Jen Psaki told reporters.

On the other hand, Kerry said in his statement that the U.S. remains willing to consider easing sanctions on Russia if and when the terms of the agreement are implemented. Those include a full cease-fire, the withdrawal of all foreign troops and equipment from Ukraine, the restoration of complete Ukrainian control of its border with Russia, and the release of all prisoners held by both sides.

More than 5,300 people have been killed in eastern Ukraine since the conflict began last year and an end to the fighting is the most immediate goal. But Ukraine and the U.S. have been particularly insistent on the border issue, maintaining that weapons, ammunition and fighters will be able to cross the frontier unless Kiev has full control.

The Minsk agreement requires the Ukrainian parliament to give wide powers to the eastern regions as a condition for restoring such control, which will not take effect until the end of this year and could then scuttle Ukrainian desires for closer ties to the west. It also appears to open the door to giving the rebels a greater amount of territory than they held at the time of the last cease-fire deal in September.

Sen. John McCain, R-Ariz., the chairman of the Senate Armed Services Committee and a frequent critic of administration foreign policy, lashed out at these apparent shortcomings, which have led some to charge that the U.S. may have lost leverage by not being directly involved in the negotiations.

"The agreement reached in Minsk freezes the conflict at a time of separatist advantage, solidifies the gains of Russian aggression and leaves Ukraine's border with Russia firmly under Moscow's control pending a comprehensive political settlement whose content is unknown and feasibility is unclear," McCain said in a statement. He added that the deal should not be used as an "excuse to delay sending defensive lethal assistance to Ukraine."

"Providing defensive lethal assistance to Ukraine is not inconsistent with the search for a political solution, it is an essential component to achieving it," he said. "Nothing about this deal has changed that."

Sen. Robert Menendez, D-N.J., ranking member of the Senate Foreign Relations Committee, sounded a similar note with regard to sanctions.

"Sanctions helped to bring Putin to the negotiating table and we should maintain this pressure until we are confident that Ukraine's territorial integrity has been fully restored," he said.

Administration officials allow that the Minsk accord is uncertain and far from perfect, but they argue that it is worth testing. And they reject suggestions that the administration was out of the loop.

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