Rishi Sunak has vowed to protect British interests abroad and at home after the RAF carried out strikes against Houthi rebels.
British and US forces struck targets in Yemen in the fifth combined operation since January.
The Ministry of Defense (MoD) confirmed it had carried out strikes against the Iran-backed group on Thursday, as a response to attacks on international shipping in the Red Sea and Gulf of Aden.
The joint British-US airstrikes killed 16 and wounded 35 others, the rebels claimed.
The Prime Minister said: “Last night the RAF successfully conducted a fifth set of strikes against Houthi military targets in Yemen alongside the US.
“These strikes were conducted to further degrade the military capabilities of the Houthis and to prevent further attacks on international shipping.
“The strikes were taken in self-defense in the face of an ongoing threat that the Houthis pose.”
Asked whether this new round of strikes risked escalation with Iran, who backs the Houthis, Mr Sunak said: “We have always said that we will not hesitate to protect British interests abroad and at home.
“There is an ongoing threat that the Houthis pose, 197 attacks since November, all our intelligence indicates that previous sets of strikes have been successful in degrading military capabilities of the Houthis: targeting supply, command and control launch sites for missiles and there is also a risk in inaction that would damage the global economy and further risk our international security.”
The MoD said intelligence had confirmed two locations near Hudaydah, around 142 miles from the capital Sana'a, as being involved with the attacks, with buildings thought to house drone ground control facilities and storage for very long range drones.
Surface-to-air weapons used to impede coalition operations to safeguard shipping in the region were also believed to be on site.
A set of Houthi facilities at Ghulayfiqah, further south on the Yemeni coast, were also identified as being involved in the command and control of the group's anti-shipping campaign.
RAF Typhoon FGR4s conducted strikes on the target buildings at the three locations, using Paveway IV guided bombs.
The MoD said the “utmost care” was taken in planning the strikes to “minimize any risk to civilians or non-military infrastructure”.
This is the fifth time the US and British militaries have conducted a combined operation against the Houthis since January 12.
The Houthis have stepped up attacks on shipping in the Red Sea and the Gulf of Aden in recent months, demanding that Israel ends the war in Gaza, which has killed more than 36,000 Palestinians.
The war began after Hamas-led militants attacked Israel on October 7, killing about 1,200 people and taking 250 hostages.
Houthi rebels have launched more than 50 attacks on shipping, seized one vessel and sunk another since November, according to the US Maritime Administration.
The attacks have disrupted shipping routes in the region.