Washington(CNN) Angela Merkel, the German chancellor desperately working to reach a diplomatic accord ending unrest in eastern Ukraine, continued her efforts at the White House Monday, urging President Barack Obama to forestall sending lethal aid to Kiev.
Her efforts appeared effective; at a midday press conference, Obama said he hadn't yet decided whether or not to send arms and equipment to besieged Ukrainian troops in the eastern part of the country.
But both leaders hinted there could be disagreements to come on how to best end the unrest that has waged for months and so far claimed 5,000 lives. Obama left open the possibility of equipping Ukrainians with American weapons if Merkel's latest attempt at brokering a diplomatic end to the violence fails.
"There may be some areas where there tactical disagreements," Obama said. "There may not be. But the broad principle that we have to stand up for, not just Ukraine, but the principle of territorial integrity and sovereignty is one where we are completely unified."
Merkel used similar language, saying through a translator the alliance between the United States and Europe will continue to stand, will continue to be solid, even though on certain issues we may not always agree."
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It was the latest bid in Merkel's shuttle diplomacy, which has taken the East Germany-born chancellor from Kiev to Moscow to the White House in just a matter of days. She's headed to Belarus for more talks on Ukraine on Wednesday.
Obama and Merkel hoped to display a united front against Russian President Vladimir Putin, whose government has backed separatists in Eastern Ukraine. Tough economic sanctions levied both by the United States and Europe have severely degraded Russia's economy, but until now haven't stopped Putin from his territorial campaign.
The united front was intact on Monday as Obama and Merkel underscored their alignment on sanctions and preference toward achieving peace through diplomacy.
"I am absolutely confident that we will do this together," Merkel said of the diplomatic efforts. "I myself actually would not be able to live with not having made this attempt."
The show of unity could be weakened if Obama decides to follow the advice of a bipartisan group of lawmakers and former administration officials pushing for greater lethal aid to Kiev. Under pressure from American lawmakers and former administration officials, the White House has said it's reconsidering whether or not to send arms to Ukrainian troops.
"It's not based on the idea that Ukraine could defeat a Russian army that was determined," Obama said of his administration's deliberations. "It is rather to see whether or not there are additional things we can do to help Ukraine bolster its defenses in the face of separatist aggression."
He failed to give a timeline for his deliberations on lethal aid to Ukraine, nor did he cite any specific move by Russia that would prompt him to decide either way.
Obama has been reluctant to send lethal aid overseas in the multiple world crises he's faced, citing the potential for the arms to wind up in the hands of enemies. In Ukraine, administration officials say they're worried that shipments of U.S. weapons could elevate the unrest there into a proxy war with Russia. And they're unsure of the Ukrainians' ability to effectively use American-supplied arms.
Republicans and Democrats have pressed the topic both in the United States and overseas. Sen. John McCain, the Republican chairman of the Senate Armed Services Committee, said at a security conference in Munich this weekend that Ukrainian troops were woefully underprepared for battle.
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"The Ukrainians are being slaughtered and we're sending them blankets and meals. Blankets don't do well against Russian tanks," McCain said, echoing the plea Ukrainian President Petro Poroshenko made to Congress in September.
Others who are closer to Obama, including the president's former Under Secretary of Defense Michele Flournoy and his current nominee to become defense secretary Ashton Carter, have also said they believe the U.S. should supply Kiev with lethal aid.
Merkel has staunchly opposed that tack, arguing more military aid could escalate the crisis further.
"The progress that Ukraine needs cannot be achieved with more weapons," she said over the weekend. "I have grave doubts about the validity of this point."
Merkel has positioned herself as the diplomatic envoy between the West and Russia, traveling to Moscow last week for closed-door meetings with Putin and French President Francois Hollande. The summit, however, concluded without a clear path toward ending the escalating violence in Eastern Ukraine.
A weekend telephone call between Merkel, Putin, Hollande and Poroshenko ended with the leaders agreeing to meet in Belarus on Wednesday, though firm details of the session weren't finalized.
The European leaders -- recognizing their country's stronger economic ties to Russia -- have been eager to broker a ceasefire diplomatically, a goal that so far has remained elusive.
Obama, who released a National Security Strategy last week with a heavy emphasis on diplomacy, has held similar views, saying the crisis in Ukraine won't end militarily.
But so far diplomacy has produced few results. A September agreement calling for drawback of heavy arms and a buffer zone disintegrated shortly after it was signed. Subsequent calls to adhere to the plan were ignored.