U.S. officials say President Donald Trump has approved an expanded military mission to secure an expanse of oil fields across eastern Syria. That raises a number of difficult legal questions about whether U.S. troops can launch strikes against Syrian, Russian or other forces if they threaten the oil.

The decision comes after a meeting Friday between Trump and his defense leaders. It locks hundreds of U.S. troops into a more complicated presence in Syria, despite Trump’s vow to get America out of the war.

Under the new plan troops would protect a large swath of land controlled by Syrian Kurdish fighters that stretches nearly 90 miles from Deir el-zour to al-Hassakeh.

Officials spoke on condition of anonymity because they weren’t authorized to speak publicly about ongoing deliberations.

(AP)