WASHINGTON — President Obamasaid Thursday evening that there was “a possibility” that a terrorist bomb was responsible for the destruction of a Russian passenger plane that broke apart last Saturday over the Sinai Peninsula in Egypt.
Mr. Obama said in a radio interview that there may have been a bomb on the plane, but he did not go as far as his counterparts in Britain, who have suggested that the destruction of the plane, and the death of all on board, was most likely the result of a terrorist explosion.
“I don’t think we know yet,” Mr. Obama told the Seattle radio station KIROduring an interview broadcast Thursday afternoon. “Whenever you’ve got a plane crash, first of all you’ve got the tragedy, you’ve got making sure there’s an investigation on site. I think there is a possibility that there was a bomb on board. And we are taking that very seriously.”
“We are going to spend a lot of time making sure our own investigators and our own intelligence community figures out exactly what’s going on before we make any definitive pronouncements,” Mr. Obama added. “But it is certainly possible that there was a bomb on board.” At the White House earlier in the day, administration officials said that the United States had not yet made a determination about the cause of the crash, which occurred after takeoff from the Egyptian resort city of Sharm el Sheikh. But they added that the government had not excluded the possibility of a bomb.
“We can’t rule anything out, including the possibility of terrorism,” Josh Earnest, the White House press secretary, told reporters in Washington.
In London on Thursday, Prime Minister David Cameron said that “more likely than not a terrorist bomb” had brought down the plane as he announced plans to bring British citizens back from Sharm el Sheikh.
Mr. Obama’s comments were the first direct indication by the president that the downing of the Russian airliner might have been something other than a technical malfunction. American officials have repeatedly cautioned that the cause of the crash is still under investigation.
Officials have noted that no American airlines fly to or from the airport in Egypt where the Russian plane began its flight. And they said before the crash, the Federal Aviation Administration had already issued guidance to airlines to fly higher above the region.
Mr. Obama’s comments came during a series of short interviews with five radio stations across the country in which the president urged people to sign up at HealthCare.gov for health insurance during the current open enrollment period. During one of the interviews, Mr. Obama was asked about the Russian plane.
In recent days, administration officials have noted the differences between the crash of the Russian plane and other airline disasters. In this case, unlike the case last year of the missing
Malaysian jetliner, the United States does not have F.B.I. agents working directly on the crash.
“Right now there are not,” Mr. Earnest said Wednesday afternoon. “Right now this is an Egyptian investigation. The Russians are involved in it.”
Officials have said American investigators were “in touch” with their counterparts in other countries who are looking into the crash. But without an American known to be on the flight — a presence that often gives officials a reason to participate in the investigation of a crash — there has been no reason for direct United States involvement, they said.
The Russians and the Egyptians have also not asked for help from the United States in the investigation, officials said.
Mr. Cameron made his remarks about the crash in an appearance at No. 10 Downing Street with President Abdel Fattah el-Sisi of Egypt.
“My role is to act in the right way to keep British citizens safe and secure,” Mr. Cameron said. He did not cite what specific intelligence he had suggesting that the explosion that destroyed the Russian plane about a half-hour after it took off from Sharm el Sheikh was deliberate.
Mr. Sisi, who has counseled against jumping to premature conclusions, did not criticize Mr. Cameron’s decision to temporarily suspend flights between Britain and Sharm el Sheikh, but Egyptian officials in Cairo did just that.
Hossam Kamal, the Egyptian minister of civil aviation, said that the suggestion of a bomb was not based on facts — and that there was as yet no evidence for that theory. The Ministry of Foreign Affairs said the British government had made the decision to halt flights unilaterally.
In a telephone conversation on Thursday with Mr. Cameron, President Vladimir V. Putin of Russia also took exception to his comments, saying that any “assessment of the causes of the crash should be based on the data” from the investigation, the Kremlin said in a statement.
While there has been much speculation about what brought down the jet, the cause largely remains a mystery. American military officials said this week that satellite surveillance had detected a flash of light as the plane was ripped apart, suggesting that it had been blown up by a bomb, an explosion caused by a mechanical failure or the ignition of fuel.
Mr. Sisi, standing next to Mr. Cameron, acknowledged that Britain had previously raised safety concerns. “Ten months ago, we were asked by our British friends to send teams to Sharm el Sheikh airport to make sure that all our security procedures there were good enough, and to provide adequate safety and security for our passengers,” he said, adding that the Egyptian authorities were ready to address any outstanding concerns.
The prime minister’s office announced later Thursday that British and Egyptian officials had “agreed on a package of additional security measures that is being put in place rapidly,” and that flights to Britain from Sharm el Sheikh would resume Friday. Two British airlines, Monarch and EasyJet, said they were ready to run flights to bring stranded tourists back to Britain from the Red Sea resort, where there are an estimated 20,000 British citizens.
Flights to Sharm el Sheikh from Britain remained suspended.
Two subsidiaries of the German airline Lufthansa, the Düsseldorf-based Eurowings and Edelweiss Air, which operates out of Zurich, suspended their Sharm el Sheikh flights on Thursday. Lufthansa said the group was working out a plan to help passengers return home.
Aleksandr Neradko, head of the Federal Air Transport Agency in Russia, said investigators in Egypt looking into the crash would be examining the wreckage of the airplane, including the hand baggage and victims’ bodies to see if there were traces of explosive substances.
Also on Thursday, the first two funerals were held for victims of the crash. The funeral for Nina Lushchenko, 60, who ran a school canteen, was a traditional Orthodox service at a 16th-century church in Veliky Novgorod, about 125 miles south of St. Petersburg.
The funeral for another victim, Aleksei Alekseev, 31, took place in St. Petersburg.