Donald Trump claims a "bomb" caused the deadly Beirut blast that killed at least 100.
The US president said he sent his sympathies to Lebanon for the dozens of people killed and thousands wounded in a massive explosion in its capital city, which he cast as an attack, and offered help.
"The United States stands ready to assist Lebanon," Trump said at a White House briefing. "We will be there to help. It looks like a terrible attack."
When asked later about his depiction of the explosion, Trump said that he had spoken with U.S. military officials who think the blast seemed to be an attack, "a bomb of some kind."
Lebanon's interior minister said initial information indicated that highly explosive material, seized years ago and which had been stored at the port, had blown up.
While President Michel Aoun said a state of emergency should be declared in Beirut for two weeks and called for an emergency cabinet meeting on Wednesday.
Aoun, in remarks published on the Presidency Twitter account, said it was "unacceptable" that 2,750 tonnes of ammonium nitrate was stored in a warehouse for six years without safety measures and vowed that those responsible would face the "harshest punishments".
Boris Johnson, meanwhile, has confirmed that British nationals are among those caught up in the aftermath of the incident.
The PM said his government is "ready to provide support in any way we can", and Foreign Secretary Dominic Raab said the UK stands in solidarity with Lebanon.
The huge explosion sent shockwaves that shattered windows,smashed masonry and shook the ground across the city on Tuesday.
The explosion was so powerful it led people to think they were caught up in an earthquake, with apartment balconies collapsing.
According to some reports, the blast was so loud it was heard in Cyprus.
The Lebanese Red Cross said hundreds of people were taken hospitals for treatment.
