The Pentagon has developed plans for an airstrike against Syrian government targets in response to this week’s apparent chemical attack by Syrian government forces, according to two U.S. military officials.

Secretary of Defense James Mattis will present the proposals to Donald Trump later today at the president’s Mar-a-Lago estate in Florida.

One of the proposals drawn up is a “saturation strike” using dozens of cruise missiles designed to hit Syrian military targets — including military air fields — in an effort to limit future Syrian Air Force attacks on rebel positions, according to the two U.S. military officials.

The officials asked for anonymity to discuss classified plans.

The proposed strike would involve launching Tomahawk cruise missiles to overwhelm Russian air defense systems used by the Syrian military. The Russian government currently helps maintain the air defense sites and advises the Syrian military.

According to both U.S. military officials, the current proposal would likely result in Russian military deaths and mark a drastic escalation of U.S. force in Syria.

One U.S. military official said the decision to allow the strikes, which would kill Russians, signals a significant change in policy by the Trump administration. A decision by Trump to go forward with the plan would be a reversal from the Obama administration, which denied multiple airstrike proposals that would likely cause Russian personnel casualties in Syria.

The Bashar al-Assad government placed many of its air defense systems in civilian areas, putting Syrian civilians at risk, according to the U.S. military and intelligence sources.

President Trump said yesterday that the Syrian government “crossed many, many lines” by conducting an apparent chemical weapons attack in Idlib on Tuesday. The attack has killed as many as 100 Syrians.

The proposed airstrike was prepared by U.S. Central Command, which oversees U.S. military operations in Syria, where a civil war has resulted in an estimated 500,000 Syrians killed, millions displaced, and an ongoing refugee crisis.

Neither the Pentagon nor CENTCOM responded to requests for comment.