Qatar and the US have warned that a new due-diligence directive risks raising energy costs and disrupting deliveries

Qatar and the United States have warned that the EU's green agenda could pose an "existential threat" to the bloc's energy security and industrial competitiveness.

In an open letter to Brussels, reported by several outlets on Wednesday, the two countries' energy ministers - Qatar's Saad bin Sherida Al Kaabi and US Secretary of Energy Chris Wright - warned that the EU's Corporate Sustainability Due Diligence Directive (CSDDD) could make gas and LNG supplies less affordable and reliable.

The US provided the bloc with 45% of its LNG in 2024. Earlier this year, Qatar, which provided the EU with 12% of its LNG in 2024, threatened to suspend all LNG exports to the bloc if Brussels proceeds with its green agenda.

Expected to take effect in 2027, the CSDDD will allow member states to fine companies up to 5% of their global turnover if their supply chains cause environmental damage or violate human rights.

The directive will "seriously undermine the ability of the American, Qatari, and broader international energy community to maintain and expand partnerships and operations within the EU," the document reads, as cited by the Qatar News Agency.

The rules come "at a critical moment," as the bloc seeks to replace Russian energy, noted the Financial Times. Since the start of the Ukraine-related sanctions campaign in 2022, the EU has shifted from Russian pipeline gas to LNG imports, mainly from the US and Qatar.

The EU's two largest economies, France and Germany, have also opposed the proposal.

The rules, set for debate by EU legislators later this week, could also jeopardize the trade deal signed in July between Brussels and US President Donald Trump, under which the bloc committed to buying $750 billion of US energy by 2028.

READ MORE: US 'ready to displace' all Russian gas and oil in EU - energy secretary

Before the Ukraine conflict, Russia supplied roughly 40% of the EU's gas through its pipeline network, much of it via Nord Stream beneath the Baltic Sea. The conduit was severely damaged by underwater explosions in 2022, widely regarded as sabotage.