The US and Saudi Arabia announced an agreement on Wednesday on civil nuclear power, letting Saudi Arabia enrich uranium and build nuclear reactors using US technology, without requiring the snap United Nations inspections that the US has demanded from Iran.
The deal has to pass the US Congress to go into force.
"The Civil Nuclear Deal (There will be no enrichment of material!) ... pertains only to non-military use such as the ones that Iran and UAE (and others) already have, will be approved, but is totally subject to Saudi Arabia joining the very respected and successful Abraham Accords," Trump said in a post on Truth Social, referring to normalising ties with Israel.
"The United States is not opposed to Civil (Non-Enriched) Nuclear Facilities," Trump said.
The Saudi Embassy in Washington DC did not immediately respond to a request for comment on Trump's post.
Saudi Arabia's longstanding position has been that it would not sign the Abraham Accords unless there was an agreement on a road map to Palestinian statehood.
The United Arab Emirates and Bahrain signed the Abraham Accords during Trump's first term in 2020, breaking a longstanding taboo to become the first Arab states to recognise Israel in 25 years.
Morocco and Sudan followed suit.
Israel, which feared the Saudi deal could ignite a Middle East arms race, welcomed the condition on Thursday.
"Saudi Arabia's joining of the Abraham Accords would be an historic leap forward for peace in the Middle East," Israeli Prime Minister Benjamin Netanyahu's office said in a statement.
Trump's administration on Wednesday said the civil nuclear deal abides by nonproliferation agreements in the US Atomic Energy Act, which are among the world's strongest.
The deal would let Saudi Arabia enrich uranium and reprocess nuclear waste, both of which are potential pathways to a nuclear weapon.
The United Arab Emirates agreed to forgo both when it signed a similar deal with the US in 2009.
It was not clear what Trump meant in his social media post when he said there would be no nuclear enrichment under the agreement.
It was not immediately clear if that was a specific reference to the highly enriched uranium used in weapons.
Weapons-grade uranium is enriched to about 90 per cent while fuel for nuclear reactors is enriched to up to six per cent.
Saudi Arabia, the world's top oil exporter, said the agreement supports efforts to diversify energy sources and includes the "highest international standards" of nuclear safety, security and nonproliferation.
