The US carried out more strikes against Houthi missiles in Yemen on Sunday, US Central Command (Centcom) said in a statement on X.
Centcom said US forces struck a land-attack cruise missile and four anti-ship missiles that “were prepared to launch against ships in the Red Sea”.
The latest military action comes a day after US-UK strikes on Houthi targets.
It follows continued attacks by the Iran-backed Yemeni group on military and shipping vessels in the Red Sea.
The Houthis’ attacks have forced major shipping companies to avoid the waterway, impacting international trade.
Egypt has said its revenue from the Suez Canal plunged by almost half in January, with the number of ships travelling through the key trade artery last month down by more than a third.
Saturday’s joint US-UK strikes lit up the night sky in the south of Yemen’s capital city of Sana’a, with one human rights activist and local resident telling the BBC houses were shaking.
Houthi officials struck a defiant tone in response to the US-led strikes – and vowed to respond.
Reacting to Saturday’s strikes, the group’s military spokesman, Yahya Sarea, wrote on X: “These attacks will not deter us from our moral, religious, and humanitarian stance in support of the resilient Palestinian people in the Gaza Strip and will not go unanswered or unpunished.”
Earlier, the White House had warned that its air strikes on Iran-backed targets in Iraq and Syria are just “the beginning, not the end” of its response to Iran.
National security adviser Jake Sullivan told US media on Sunday “there will be more steps”.
The US is responding to the deaths of three soldiers in an enemy drone attack on a military base in Jordan last week.
Iran has denied having any involvement in the drone attack, and its affiliate, the Islamic Resistance in Iraq, has claimed responsibility.
The US accuses Tehran of having its “fingerprints” on the attack and said the drone was Iranian-made.
In a letter to Congress on Sunday, President Joe Biden said the retaliatory strikes on Friday had targeted facilities used by Iran’s armed forces – the Islamic Revolutionary Guard Corps (IRGC) – and militia groups linked to the IRGC.
Iran’s IRGC is believed to have armed, funded and trained Islamic Resistance in Iraq.
Mr Biden said sites hit included those used for “command and control, weapons storage, training, logistics support, and other purposes”.
And he added that the strikes aimed to deter these groups from further attacks, and were taken in a way “to limit the risk of escalation and avoid civilian casualties”.
He also said that he would “direct additional measures, including against the IRGC and IRGC-affiliated personnel and facilities, as appropriate”.