WASHINGTON (AP) — President Barack Obama pressed skeptical lawmakers to give him the authority to use U.S. military force against Syria during his overseas trip while the administration struggled to rally international support for intervention in an intractable civil war.

Obama was making calls to members of Congress while he attends an economic summit in St. Petersburg, Russia, Ben Rhodes, Obama’s deputy national security adviser, told reporters on Thursday. The president spoke to a bipartisan group of five lawmakers on Wednesday.