The United Auto Workers union called a nationwide strike against General Motors Sunday, with some 46,000 members set to walk off the job beginning at midnight amid an impasse in contract talks.

The decision, which the Wall Street Journal described as the first major stoppage at GM in more than a decade, came a day after the manufacturer's four-year contract with workers expired without an agreement on a replacement.

Local union leaders met in Detroit "and opted to strike at midnight on Sunday," the UAW said on its Twitter account.

"This is our last resort," Terry Dittes, the union's lead negotiator with GM, told a news conference after the meeting. "We are standing up for the fundamental rights of working people in this country."

Saudi Arabia raced on Sunday to restart operations at oil plants hit by drone attacks which slashed its production by half, as Iran dismissed US claims it was behind the assault.

The Tehran-backed Huthi rebels in neighbouring Yemen, where a Saudi-led coalition is bogged down in a five-year war, claimed Saturday's strikes on two plants owned by state energy giant Aramco.

But US Secretary of State Mike Pompeo pointed the finger squarely at Tehran, saying there was no evidence the "unprecedented attack on the world's energy supply" was launched from Yemen.

"The United States will work with our partners and allies to ensure that energy markets remain well supplied and Iran is held accountable for its aggression," the top US diplomat added.