US opposition to an Israeli strike on Iran’s nuclear program may be softening, a former head of IDF intelligence said Wednesday.

“The American stance on an Israeli strike against Iran has changed dramatically recently,” said Amos Yadlin, who served as chief of the IDF’s Intelligence Directorate from 2006 to 2010.

“In 2012 the [Americans'] red light was as red as it can get, the brightest red,” Yadlin said in an interview with Army Radio Wednesday morning. “But the music I’m hearing lately from Washington says, ‘If this is truly an overriding Israeli security interest, and you think you want to strike,’ then the light hasn’t changed to green, I think, but it’s definitely yellow.”

Yadlin is thought to be close to parts of the US defense establishment. He served as Israel’s military attache in Washington from 2004 to 2006, and was a Kay Fellow in Israeli national security at the Washington Institute for Near East Policy in 2011.

In April, Yadlin told a conference at the Institute for National Security Studies, which he heads, that Israel would have to make a decision on striking Iran by the summer of this year.

“For all intents and purposes, Iran has crossed Israel’s red line… in the summer, Iran will be a month or two away from deciding about a bomb.”

Prime Minister Benjamin Netanyahu responded to Yadlin’s comments then by saying Iran had not yet crossed his “red line.”

Yadlin is a veteran of Israeli anti-nuclear strikes in the past. He was one of the eight pilots who conducted Operation Opera, which destroyed Iraq’s nuclear reactor at Osirak in 1981, and was head of IDF intelligence during the September 2007 strike against Syria’s fledgling nuclear program deep in the country’s northern desert.

Israel has not formally acknowledged responsibility for the Syria strike, but is widely believed, including by former senior officials, to have carried it out.

Yadlin’s comments came on the heels of a Tuesday press conference in Tehran in which Iran’s new president, Hasan Rouhani, said Iran is ready for “serious” and swift talks with world powers over its controversial nuclear program.

The press conference was Rouhani’s first as Iran’s president, and was immediately dismissed by Netanyahu, who called for increased pressure on the Iranian regime.

The cleric won a landslide victory in June presidential elections and took the oath of office on Sunday.

“We are ready to engage in serious and substantial talks without wasting time,” Rouhani said, but warned that Iran’s interactions with the West should be based on “talks, not threats.”

Many Iranians and foreign diplomats hope Rouhani, a former top nuclear negotiator, can strike a more conciliatory tone in the talks. Four rounds of negotiations since last year have failed to make significant headway.

But in Israel, Netanyahu urged the international community to step up pressure on Tehran.

“Iran’s president said that pressure won’t work. Not true! The only thing that has worked in the last two decades is pressure. And the only thing that will work now is increased pressure,” Netanyahu said in comments released by his office after meeting with US lawmakers.

Netanyahu has said that despite Rouhani’s moderate speech, he believes the Iranian leader backs enriching uranium for nuclear weapons.

The US and its allies fear Iran is trying to develop a nuclear weapon, a charge Tehran denies, saying its atomic program is meant for peaceful purposes only.

Rouhani replaced Ahmadinejad, who struck a hardline approach when dealing with the West and its sanctions over Iran’s nuclear program. The sanctions have hit the country’s economy hard, decimating its vital oil exports and blocking transactions on international banking networks.

Though all Iranian policies, including the nuclear issue, are firmly in the hands of Supreme Leader Ayatollah Ali Khamenei, a strong president can influence decision-making. Rouhani has in the past said that he would make it his priority to get the sanctions against Iran lifted.

“I, as the president of Iran, announce that Iran has a serious political will to solve the (nuclear) problem while protecting the rights of the Iranian people at the same time as it seeks to remove concerns of the other party,” Rouhani told reporters in Tehran.

Rouhani’s inauguration “presents an opportunity for Iran to act quickly to resolve the international community’s deep concerns over their nuclear program,” said US State Department spokeswoman Jen Psaki.

But she added, “there are steps they need to take to meet their international obligations and find a peaceful solution to this issue, and the ball is in their court.”

Earlier on Tuesday, the European Union’s foreign policy chief, Catherine Ashton, called on Rouhani to schedule “meaningful talks” on the nuclear issue as soon as possible.

Spokesman Michael Mann said Ashton congratulated Rouhani on his inauguration and urged him to use his strong mandate “to seek a swift resolution to (the international community’s) serious concerns about Iran’s nuclear activities.”

Ashton said she and the group of nations negotiating with Iran — the five permanent UN Security Council nations plus Germany — “stand ready to continue talks to find a resolution as quickly as possible.”

Rouhani has repeatedly said that he believes it’s possible to strike an agreement that would allow the Islamic Republic to keep enriching uranium — the core issue at the center of the nuclear controversy and a potential pathway to atomic weapons — while assuring the West it will not produce nuclear arms.

On Tuesday, he said uranium enrichment is Iran’s right, as it is for any other country, but that he would look to “remove mutual concerns, achieve mutual interests and a win-win deal for both sides.”

In efforts to get Iran to account for its nuclear ambitions, President Barack Obama and other Western leaders remain publicly committed to diplomacy though they stress military options against Iranian nuclear sites are not off the table.

Rouhani indicated he would “not have any problem to talk” directly to Washington and to “whoever wants to talk to us in good will … even if it is the US,” as long as the other party is “serious about talks and abandons the language of pressure and threat.”

Rouhani admitted, however, that there is a “long way to go until the point” when Iran would allow the US consulate to resume work in Tehran.

The United States cut diplomatic ties with Iran after militant students stormed the US Embassy in Tehran to protest Washington’s support for deposed Shah Mohammad Reza Pahlavi following the country’s 1979 revolution. The revolution toppled the pro-US monarchy and brought Islamic clerics to power.

Times of Israel staff contributed to this report.