The premier confirmed Monday that investigators believe the IS carried out Saturday's attack, though no group has taken responsibility.
"We are primarily focusing on Islamic State," Davutoglu said in a live interview with NTV, adding that the attack will not "turn Turkey into Syria."
Turkish authorities initially suggested Kurdish rebels and far-left radical groups could also have been capable of carrying out the bombings. Authorities were close to identifying one of the suicide bombers through DNA tests, which will help determine what group was responsible.
The bombings, considered the deadliest terror attack in modern Turkish history, happened seconds apart near Ankara's main train station as hundreds were preparing for a lunchtime peace rally in Sihhiye Square.
Turkey declared three days of mourning following the attack, which also injured about 250 people.
Video footage showed a group of young people holding hands and singing before the first explosion. The peace rally was to call for the end to conflict between the Kurdistan Workers' Party, or PKK, and the Turkish state.
Many have blamed the Turkish government for failing to provide appropriate security measures that could have prevented the bombing. Two of Turkey's main labor unions began a two-day strike on Monday to protest the government's failure to prevent the bombings.
The attacks happened ahead of a re-election on Nov. 1 after a failed vote to elect a single-party government. Turkey is part of the U.S.-led coalition against the IS -- also identified as Daesh, ISIS and ISIL. Turkey has allowed the United States to launch airstrikes from the Incirlik Air Base.
Davutoglu said Saturday's bombing were an attempt to influence the upcoming elections. Many of the victims of the bombings were activists for the pro-Kurdish HDP party, which believes it was specifically targeted in the attack.