US President Barack Obama urged Iranian Supreme Leader Ayatollah Khamenei to reach a deal on Iran’s nuclear program and join the US against Islamic State (ISIS) in a secret letter he sent in mid-October, according to senior officials.

The Obama administration did not deny the letter, but they never informed Israel, Saudi Arabia, or the United Arab Emirates about it. These three countries have raised concerns about the nuclear arms race Iran’s program could spur.

Khamenei has called for Israel’s destruction, and has blamed America for creating ISIS. A senior Israeli source revealed two weeks ago that Obama might be conferencing with Iran in secret.