WASHINGTON -- Speaking for the first time in more than two weeks, President Obama and Russian President Vladimir Putin showed little sign of agreement on Monday, with the U.S. leader urging pro-Russian forces to de-escalate the situation in eastern Ukraine and Putin denying that Moscow was interfering in the region.
The White House said Russia initiated the phone call, which came as pro-Russian forces deepened their insurgency in Ukraine's east, seizing more than a dozen government buildings.
"The president expressed grave concern about Russian government support for the actions of armed, pro-Russian separatists who threaten to undermine and destabilize the government of Ukraine," the White House said in a description of Obama's call with Putin. "The president emphasized that all irregular forces in the country need to lay down their arms, and he urged President Putin to use his influence with these armed, pro-Russian groups to convince them to depart the buildings they have seized."
In its own description of the call, the Kremlin said Putin told Obama reports of Russian interference in the region were "based on unreliable information." The Russian leader also urged Obama to discourage the Ukrainian government from using force against those protesters.
Both sides did suggest that plans would go forward for talks Thursday in Geneva between the U.S., Russia, Ukraine and Europe. But the White House said Obama told Putin that while a diplomatic solution remained his preferred option, "it cannot succeed in an environment of Russian military intimidation on Ukraine's borders, armed provocation within Ukraine, and escalatory rhetoric by Kremlin officials."
The phone call came on a day when the Pentagon confirmed that a Russian SU-24 fighter jet had made several low altitude, close passes in the vicinity of the USS Donald Cook in international waters of the western Black Sea on April 12.
While the jet did not overfly the U.S. warship's deck, Col. Steve Warren called the action "provocative and unprofessional." The close-flying jet came within a few thousand feet of the USS Donald Cook, a guided missile destroyer which was conducting a "routine mission" at the time.
The U.S. ship tried to contact the plane's cockpit, but received no response. The Russian plane, which the U.S. says was unarmed, made at least 12 passes. This continued for about 90 minutes but the event ended without incident. The USS Donald Cook was docked Monday at the Romanian Black Sea port of Constanta.
Earlier this month, the Pentagon announced it would be sending a second warship into the Black Sea to conduct exercises with "our Black Sea partners," CBS News correspondent David Martin reported.
U.S. officials say there is compelling evidence that Russia is fomenting the unrest in eastern Ukraine, but have suggested Obama has not yet concluded that Putin's actions warrant broader sanctions on key Russian economic sectors.
"We are actively evaluating what is happening in eastern Ukraine, what actions Russia has taken, what transgressions they've engaged in," White House spokesman Jay Carney said. "And we are working with our partners and assessing for ourselves what response we may choose."
Administration officials confirmed Monday that CIA chief John Brennan visited the Ukrainian capital of Kiev over the weekend, breaking with the administration's typical practice of not disclosing the director's travel. Ousted Ukrainian President Viktor Yanukovych accused Brennan of being behind Ukraine's decision to send troops into the east to try to quash an increasingly brazen pro-Russian insurgency.
While U.S. officials denied those accusations, confirmation of Brennan's visit could provide fodder for Russian officials to create a pretext for further incursions into eastern Ukraine.
Obama and Putin last spoke on March 28. Since then, pro-Russian forces have undertaken a rampage of storming and occupying local government offices, police stations and a small airport in eastern Ukraine. The Ukrainian government has proved powerless to rein in the separatists, who are demanding more autonomy from the central government in Kiev and closer ties to Russia.
The White House has blamed the unrest on Russia, saying there are undeniable similarities between the situation in eastern Ukraine and the Kremlin's maneuvers in Crimea, the Black Sea peninsula Russia annexed from Ukraine last month.
"The evidence is compelling that Russia is supporting these efforts and involved in these efforts," Carney said. "You saw this coordinated effort in a number of cities across eastern Ukraine all at once that sure didn't look organic to observers from the outside."
Despite those assertions, it was unclear whether the U.S. planned to respond with deeper economic penalties. Obama has repeatedly warned that Russian advances into eastern Ukraine would mark a serious escalation of the crisis that would warrant a stronger international response, including the prospect of sanctions on Russia's energy sector and other key industries.
But the administration has avoided saying whether Russia's actions in the east thus far have crossed that line.
Obama is once again faced with the complicated reality of following through on his tough warnings against overseas provocations.
Obama has vowed to enact biting sanctions against Russia's vital economic sectors if the Kremlin tries to replicate its actions in taking over Crimea elsewhere in Ukraine. But despite those warnings, Russia appears to be testing Obama's limits.
For Obama, the U.S. response to the chaos in Ukraine has become more than a test of his ability to stop Russia's advances. It's also being viewed through the prism of his decision last summer to back away from his threat to launch a military strike when Syria's government crossed his chemical weapons "red line."
U.S. officials are also still trying to rally support for sector sanctions from Europe, which has a far deeper economic relationship with Russia and would therefore be more likely to be negatively affected by the penalties.
As part of that effort, Obama spoke Monday with French President Francois Hollande. The French leader said in a statement that he and Obama discussed the importance of avoiding provocations in Ukraine and establishing a policy of strong and calibrated sanctions along with other European partners.
A high-ranking European Union official said foreign ministers did decide Monday to sanction more Russians with asset freezes and visa bans, though they appeared to stop short of the broader penalties on Russia's economy.