• GM says it "believes in an all-electric future."

• The carmaker will introduce at least 20 new all-electric vehicles by 2023

• Two new EVs will hit the market by 2018, following the Chevy Bolt which was launched in 2016.

• GM will also pursue a hydrogen fuel-cell electric strategy, to address the needs of non-retail customers

General Motors unveiled on Monday an ambitious plan to become an all-electric automaker, using a strategy that would combine battery-electric and fuel-cell-electric vehicles.

The move demonstrated that GM is serious about remaining not just relevant, but extremely competitive as the global auto industry is transformed by electrification and the arrival of upstarts such as Tesla.

"General Motors believes the future is all electric," Mark Reuss, the carmaker's Executive Vice President of Global Product Development, said on a conference call with reporters after sharing details of forthcoming designs and new battery engineering was revealed. The 109-year-old company made the announcement in Detroit.

"These aren't just words in a war of press releases" Reuss added, stressing that CEO Mary Barra has been linking GM's zero-emissions and autonomous-driving objectives for several years. The company has demonstrated this by rolling out its all-electric Chevy Bolt EV and making progress on fully self-driving cars through its acquisition of Cruise Automation and the creation of its Maven ride-hailing and ride-sharing brand.

Reuss said that GM would follow the Bolt, which went on sale late last year, with two additional all-electric vehicles by 2018. At least 20 all-electric vehicles will arrive by 2023.

The auto industry has been abuzz lately as companies jockey to position themselves for full-electrification of their products, driven by regulatory changes and the possibility that major growth markets, mainly China, will ban internal-combustion engines.

The internal-combustion engine lives on — for now

The Chevy Bolt is about to get some company. GM

Reuss took note of the moves made by carmakers such as Volvo to commit to an all-electric future, but on a conference call with the media he declined to detail GM's timetable. He said that if an automaker was making those kinds of predictions, they probably don't have a lineup that's as large as GMs, which ranges from small cars to heavy-duty trucks.

"We can't just flip a switch and make the world go all-electric," he said, adding that GM will continue to enhance the efficiency of internal-combustion engines until an all-electric future arrives.

GM's two-pronged electrification approach was unexpected, although over the years the company has indicated that hydrogen fuel-cell could be as promising as all-electric propulsion technologies.

GM also revealed a new battery architecture that it said would provide greater flexibility to engineer cars and trucks in response to customer demand. But it also said that "getting to a zero emissions future will require more than just battery-electric technology."

To that end, the company revealed a design for a new heavy-duty vehicle platform that would be powered by fuel-cell and dual electric motors, called "SURUS," or "Silent Utility Rover Universal Superstructure."

"With its capability and flexible architecture, SURUS could be used as a delivery vehicle, truck or even an ambulance — all emissions free," GM said.

GM shares were up 4%, to $42, though most of those gains came ahead of the news. The stock is up about 20% since the beginning of 2017.