The White House says President Barack Obama spoke Tuesday with his Russian counterpart Vladimir Putin on how to ensure a safe and secure Sochi Olympics. A White House statement says Washington is offering its "full assistance."
The top-level conversation came a day after the Pentagon said it offered Moscow air and naval assets to help secure the resort city area. It also came as Russian police continued the hunt for at least three potential suicide bombers, including a woman thought to have penetrated a security perimeter surrounding the city. The Winter Olympics are set to begin next month.
Witnesses in Sochi say police have distributed photos of the female suspect, who is said to be the widow of an Islamic militant from the predominantly Muslim region of Dagestan. She has been identified as 22-year-old Ruzanna Ibragimova, nicknamed "Salima."
Russian officials have blamed the so-called "black widows" of slain insurgents for previous suicide attacks in the country.
On Sunday, an Islamic militant group from Dagestan posted a video online claiming responsibility for last month's deadly suicide bombings in Volgograd, which killed 34 people. The two men in the video also threaten attacks at the Olympics. It is unclear when the video was made.
Thousands of athletes and spectators from all over the world are expected to travel to Sochi for the Olympic Games, which will feature competitors in a variety of winter sports, including skiing, skating and ice hockey.
Andrew Kuchins, the director of the Russia and Eurasia Program at the Center for Strategic and International Studies in Washington, told reporters Tuesday that security in Sochi is not the only Russian security concern.
"You don't necessarily have to hit Sochi to spoil the games," he said. "A series of Volgograd attacks would terrorize the whole of Russia and spoil the games and that will be a great tragedy."
Russian President Vladimir Putin said in comments broadcast Sunday that his country will do "whatever it takes" to ensure security at the Olympics.
He spoke about massive security preparations in and around Sochi and said: "If we betray weakness, betray fear -- display our fear -- then we will be helping terrorists achieve their goals."