He also alluded to concerns about European dependence on Russian gas imports via the contentious Nord Stream 2 pipeline, construction of which has been held up by US sanctions, and said LNG imports could help solve Europe's energy issues.

Trump noted US gas supplies were becoming increasingly available thanks to the energy "revolution" brought about by shale production.

"While many European countries struggle with crippling energy costs, the American energy revolution is saving American families $2,500 every year in lowering electricity bills... and also very importantly prices at the pump," Trump said, in comments webcast from the venue.

"The US no longer needs to import energy. With an abundance of American natural gas now available, our European allies no longer have to be vulnerable to unfriendly energy suppliers either," he said.

"We urge our friends in Europe to use America's vast supply and achieve true energy security. With US companies and researchers leading the way we are on the threshold of virtually unlimited reserves of energy including from traditional fuels, LNG, clean coal, next-generation nuclear power and gas hydrate technologies."

Referring to rising concern about carbon emissions and climate change, Trump said innovation and technology could overcome all challenges, while also taking an apparent swipe at some of his political rivals in the US with a mention of "radical socialists" out to destroy the economy.

"To embrace the possibilities of tomorrow we must reject the perennial prophets of doom and their predictions of the apocalypse...the heirs of yesterday's foolish fortune-tellers. We understand what the pessimists refuse to see, that a growing and vibrant market economy focused on the future lifts the human spirit and excites creativity strong enough to overcome any challenge by far. We continue to embrace technology, not to shun it," Trump said, adding the US was joining in a World Economic Forum plan to plant a trillion trees.

The comments contrasted starkly with those of Thunberg, who told the forum time was running out to restrict global average temperature increases to 1.5 degrees Celsius and people were already dying as a result of climate change.

The world could only afford to emit CO2 at current levels for another eight years if temperature increases are to be kept within 1.5 C, Thunberg said, adding that "every fraction of a degree matters".

Burgeoning LNG

Since US LNG exports from the Lower 48 began in February 2016, Europe has received 28.3 Bcm of gas equivalent, according to data from S&P Global Platts Analytics. Volumes have risen quickly over the past year thanks to the increase in US export capacity and Europe playing the role of market-of-last-resort for surplus cargoes, in an oversupplied global market.

In 2019, US LNG exports to Europe totaled 20.3 Bcm of gas equivalent, up from 4.7 Bcm the previous year.

That means US LNG exports to Europe are now on a par with Europe's pipeline imports from Algeria, which totaled 21 Bcm in 2019, according to Platts Analytics data.

The main markets for US LNG since February 2016 have been Spain and the UK, which have imported 6.04 Bcm and 4.98 Bcm, respectively, to date. Both countries are easily reached from the US Gulf of Mexico and have plenty of LNG import capacity.

The other main importers to date have been: France (3.82 Bcm), Turkey (2.68 Bcm), Italy (2.71 Bcm), Portugal (2.66 Bcm) and the Netherlands (2.43 Bcm), with smaller volumes landing in Belgium, Greece, Lithuania, Malta and Poland.