International Olympic Committee president Thomas Bach says he has confidence that Russian authorities will deliver a safe and secure Games in Sochi after two deadly bombings hit the city of Volgograd.
Mr Bach expressed his condolences for the despicable attacks in the southern city on Sunday and Monday, which killed 31 people.
He said he is certain that everything will be done to ensure the security of the athletes and all participants of the 2014 Winter Olympics which open on 7 February, the BBC reports.
Russia's foreign ministry did not blame any particular group, but likened the attacks to acts by militants in the United States, Syria and elsewhere.
President Vladimir Putin has called for security to be stepped up at stations and airports throughout the country.
Moscow is concerned that militant groups could be ramping up violence in the run-up to the Games at Sochi which is right on the edge of Russia's troubled Caucasus republics and their long-running Islamist insurgency.
Investigators say at least 14 people were killed in a suicide bombing on a trolleybus in Volgograd during the Monday morning rush hour.
It came a day after 17 people died in another suicide attack at the central station in the city. Scores were injured in the attacks.
Volgograd was also targeted in October this year, when a suspected female suicide bomber killed six people in an attack on a bus.
The United States has offered full security support to Russia, saying it would welcome closer cooperation to ensure the safety of athletes and spectators. A spokeswoman for the State Department, Maire Huff, said the US has been working with Russia in the lead-up to the Games.
New Zealand's Olympic officials say the bombings will not stop athletes participating in the Sochi Games.