TEL AVIV — Israel’s senior military intelligence analyst said Tuesday that there was evidence the Syrian government had repeatedly used chemical weapons in the last month, and he criticized the international community for failing to respond, intensifying pressure on the Obama administration to intervene.
“The regime has increasingly used chemical weapons,’’ said Brigadier General Itai Brun, research commander in the intelligence directorate of the Israeli Defense Forces, echoing a recent finding by Britain and France.
‘‘The very fact that they have used chemical weapons without any appropriate reaction,’’ he added, ‘‘is a very worrying development, because it might signal that this is legitimate.’’
Brun’s statements are the most definitive by an Israeli official to date regarding evidence of chemical weapons attacks on March 19 near Aleppo and Damascus.
Another military official, speaking on the condition of anonymity, said that the evidence had been presented to the Obama administration — which has declared the use of chemicals a ‘‘red line’’ that could prompt US action in Syria — but that Washington has not fully accepted the analysis.
None of the assertions — by Israel, Britain, or France — have been made with physical proof of chemical weapons use. Specialists say the most definitive way to prove the use of chemical weapons is to promptly gain access to the site to collect soil samples and examine suspected victims.
The Syrian government, which has accused insurgents of using chemical weapons and has requested that a United Nations forensics team investigate, has so far refused to allow that team to enter because of a dispute over the scope of its inquiry.
In Brussels, at a meeting of NATO foreign ministers, Secretary of State John Kerry urged that the alliance be ready to respond if Syria used chemical weapons. ‘‘We should also carefully and collectively consider how NATO is prepared to respond to protect its members from a Syrian threat, including any potential chemical weapons threat,’’ Reuters quoted him as saying.
He did not specify in his publicly released remarks what planning he wanted from members of the NATO alliance.
Kerry also said he had
talked by telephone Tuesday morning with Prime Minister Benjamin Netanyahu of Israel, and that Netanyahu had told him that he could not confirm the assertions of chemical weapons use.
‘‘I don’t know yet what the facts are,’’ Kerry added. ‘‘I don’t think anybody knows what they are.’’
A spokesman for Netanyahu refused to comment on the telephone call on the apparent disconnect between the prime minister and his military leaders.
In briefings on Tuesday, the Israelis said they believed that the attacks March 19 involved the use of sarin gas, the same agent used in a 1995 attack in the Tokyo subway that killed 13.
The Syrian attacks killed ‘‘a couple of dozens,’’ the military official said, in what Israel judged as ‘‘a test’’ by President Bashar Assad of the international community’s response. He said the government had deployed chemicals a handful of times since, but that details of those attacks were sketchier.
‘‘Their fear of using it is much lower than before using it,’’ the official said. ‘‘If somebody would take any reaction, maybe it would deter them from using it again.’’
Regarding possible further attacks, he added, ‘‘Now I’m more worried than I was before.’’
Israel, which is in a technical state of war with Syria, has been deeply reluctant to act on its own in Syria, for fear that it could bolster Assad by uniting anti-Israel sentiment. But the public statements regarding the attacks, days after the British and French governments wrote to the UN secretary-general saying they, too, had evidence of chemical use, complicates the situation for officials in Washington.
President Obama said last month during his visit to Israel that proof of chemical weapons use would be a ‘‘game changer.’’ But Defense Secretary Chuck Hagel said Monday that the intelligence regarding the attacks remained inconclusive, and his press secretary, George Little, said Tuesday that the Pentagon was continuing to assess reports on the matter.
‘‘The use of such weapons would be entirely unacceptable,’’ Little said in Amman, Jordan, where Hagel landed Tuesday. ‘‘We reiterate in the strongest possible terms the obligations of the Syrian regime to safeguard its chemical weapons stockpiles, and not to use or transfer such weapons to terrorist groups like Hezbollah.’’
Though the Assad government had claimed last month that it was the rebels who used chemicals, Brun echoed previous statements by Israeli and US officials that it was clearly the Syrian government, and not the opposition, that had conducted the attacks.
Israeli military officials said that during the past few months Syria has sharply consolidated its chemical stockpiles, reducing the number of sites by about half to retain greater control over the arsenal. The weapons are now stored in 15 to 20 sites, they said.
If US officials have been more reluctant that their allies to come to firm conclusions, it may be because it would force Obama’s hand. In August, the president told reporters that any evidence that Assad was moving the weapons or making use of them could prompt the United States to act.