Foreign Secretary David Cameron said the UK is "prepared to back our words with actions" against the Houthis, after taking military action in Yemen over their attacks in the Red Sea.
Lord Cameron said the US-UK air strikes were needed after months of attacks on shipping, despite warnings.
Sir Keir Starmer said he backed the operation as "action had to be taken".
But the Labour leader said he would have to consider whether to support any more air strikes.
Looking at the global security situation more generally on the BBC's Sunday with Laura Kuenssberg programme, Lord Cameron cautioned it is "hard to remember a more unstable, dangerous and uncertain world".
He said the "red lights on the global dashboard are very much flashing", given ongoing wars in Ukraine, the Middle East and Africa.
Lord Cameron said the UK had given the Houthis, who are key allies of Hamas, "warning after warning" before joining US-led strikes, which were launched to protect global shipping.
The Houthis are a political and military group which control a large part of Yemen, including the capital. They are backed by Iran, Israel's arch-enemy and claim they target any ship travelling to, or owned by, Israel.
They have carried out at least 27 attacks since 19 November, according to the US, and have launched a series of drones and missiles towards Israel.
The group's attacks on cargo ships - some of which have no clear connection to Israel - have led major shipping companies to divert vessels away from the Red Sea, instead taking a longer route around southern Africa.
Confirming there would be a statement in Parliament about the strikes on Monday, Lord Cameron said a political debate before this kind of military action would not have been right "for reasons of operational security".
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