President Obama stated clearly that the U.S. is not considering arming or providing lethal aid to Ukraine to defend its sovereignty against pro-Russian forces.

“I've been very clear that military options are not on the table in Ukraine because this is not a situation that would be amenable to a military solution,” he told reporters Thursday afternoon during a White House press conference.

Obama made the statement in response to questions on whether the U.S. was considering providing any arms to Ukraine.

The president said he hoped Russia will abide by an agreement struck Thursday in Geneva between Russian, Ukrainian, U.S. and European officials. The goal of that preliminary deal, Obama said, is to have pro-Russian “irregular forces” that are active in Ukraine disarm and stop seizing government buildings and territory so Kiev can move forward with elections and “start getting their economic house in order.”

After the talks in Geneva, earlier Thursday, Secretary of State John Kerry said Russia has agreed to refrain from violence and from encouraging separatist groups. In return, Ukraine has pledged amnesty to all of the pro-Russian separatists who have seized territory in eastern Ukraine as long as they lay down their weapons and disperse.

Obama cautioned that the agreement could fall apart at any moment but he was hopeful that the Russians would take the steps necessary to de-escalate the situation.

“I don't think we can be sure of anything at this point,” he said. “I think there is a prospect that diplomacy can de-escalate the situation… and move on to what has always been our goal – to have Ukrainians control their own lives.”

Over the last two months as tensions in the region mounted and Russia annexed Crimea, Republicans have criticized President Obama for failing to intervene more directly and provide more support to Ukraine and other countries in eastern Europe.

After Obama's press conference, a spokesman for Speaker John Boehner, R-Ohio, said the Russians shouldn't be trusted unless they agree to hand Crimea back to Ukraine.

“If the Russians want to show they are serious about de-escalation, they'll leave Crimea,” said Boehner spokesman Brendan Buck.

Earlier Thursday on a Kentucky radio show, Senate Minority Leader Mitch McConnell, R-Ky., amplified that message, saying he would push back against Russia much more aggressively by providing arms to the Ukrainian army and revisiting the idea of developing a missile defense shield with key eastern European countries.

“Here is what I would do: I would be sending arms to the Ukrainian army. I would encourage the European Union to expand and take in Ukraine… I would provide serious assistance to the Ukrainians so that they could defend themselves,” he said.

“I would renew the discussions that the president just dropped, the idea of missile defense and the Czech Republic and Poland at the beginning of his term as a sort of a gesture to the Russians. I would re-engage with the Pols and the Czechs and see if we can't get missile defense back in those countries,” McConnell continued.

“All of those steps would indicate without sending in a single American soldier that the U.S. is serious in standing up to this kind of new form of Russian aggression,” he added.

Shortly after the press conference was over, the White House released a read-out of a phone call Obama had with German Chancellor Angela Merkel in which the two stressed the need for Russia to take “immediate, concrete actions” to de-escalate the situation in eastern Ukraine.

Obama said he also planned to call British Prime Minister David Cameron to discuss the situation.

This story was published at 4:28 p.m. and has been updated.