Stock futures were down on Monday as investors continue to eye developments in U.S.-Iran peace negotiations.

Iran and the U.S. agreed to the creation of a mechanism to ensure the termination of military operations in Lebanon, mediators said.

Oil prices were down, with Brent crude trading below $80 a barrel.

"Recent developments show that moving towards a more permanent deal will be challenging," ING said. "The key factor is still whether oil and LNG flows from the Persian Gulf continue to recover, despite all the rhetoric."

Looking ahead, U.S. PCE inflation data and provisional purchasing managers' survey figures on Thursday will be watched closely after the Federal Reserve recently signaled the possibility that its next move could be to raise interest rates.