The heads of oil giants BP and Royal Dutch Shell have said Donald Trump's withdrawal from the Paris climate agreement will not slow investment in renewable energy.
Shell chief executive Ben van Beurden said that the "energy transition" - which will see renewable sources of energy playing a bigger role alongside hydrocarbons such as oil and gas - is "unstoppable".
"It's not just because we all believe that climate change is real and we need to do something about it, that may be one important factor.
"But ultimately it is both policy, public sentiment but also technology that is driving it, and it is fundamentally a force that cannot be stopped, irrespective of what individual actors - even if they are large actors like the United States - decide to do in relation to Paris," he said during a panel at the St Petersburg International Economic Forum in Russia.
Mr van Beurden's comments come just weeks after the oil giant faced criticism from shareholders over its climate change commitments, having rejected a proposal that would have required the company to adopt emissions targets that would bring it in line with the Paris accord.
At Shell's annual general meeting on May 23, Mr van Beurden insisted Shell was making progress in lowering its emissions, but that achieving Paris climate agreement goals - which aim to limit global warming to below 2C from pre-industrial levels - would require broader co-ordination, including active government support.
In St Petersburg, BP chief executive Bob Dudley said that while the US might not be part of the Paris framework, he suspects that "lower carbon energy" will continue to be developed across the country.
"As a commercial company our strategy is not taking a different direction by the announcement yesterday," he said.
"We're a long-term company, we have oil and gas, renewable energies, we'll remain committed to those. We realise that this is a transition that will come over time."