The UK has confirmed its support for the Saudi-led "Firmness Storm" military operation in Yemen.
The UK”s Foreign Ministry said the operation came after a request from the Yemeni President Abd Rabou Mansour Hadi.
On Wednesday night Saudi Arabia launched air strikes in Yemen.
The Gulf kingdom said the operation targeted Shia Houthi rebels.
The Saudi-led military operation in Yemen started two days after the British Foreign Secretary Philip Hammond visited Riyadh where he reiterated his country's cooperation with the Gulf Kingdom to meet its “commitment to the security and stability of the region.”
Hammond also reconfirmed the UK's support for Hadi as “Yemen’s legitimate president.”
“The UK is extremely concerned about the deteriorating security situation in Yemen,” he said in an official statement
Hammond added that “Saudi Arabia’s leadership in dealing with this worsening problem is very much valued."
In an official statement on Thursday, a spokeswoman for the UK”s FM said that Hadi asked for support by "all means and measures to protect Yemen and deter Houthi aggression."
The spokeswomen also added added that he UN Security Council made clear that Hadi is Yemen's legitimate president.
The media in Saudi Arabia said that the kingdom's army is supplying 100 warplanes and 150,000 soldiers for the operation.
The official Saudi Press Agency said Gulf Cooperation Council members Saudi Arabia, Bahrain, Kuwait, Qatar and the United Arab Emirates agreed to answer Hadi's call for help.
Oman , another GCC member, has not supported the military action.
The Saudi media also said war planes from Egypt, Morocco, Jordan, Sudan, Kuwait, the United Arab Emirates, Qatar and Bahrain were taking part in the operation in Yemen.
London blamed the Houthi rebels for the dramatic developments which have led to foreign military intervention.
“The recent Houthi actions and expansion in Aden and Taiz is a further signal of their disregard for the political process. Any action taken should be in accordance with international law,” the spokeswoman said.
However, the policy of the UK, which is the mentor of the Yemeni crisis in the UN, suggests negotiations are the only way to settle the escalating problem.
“Ultimately, the solution to the crisis must be a political one."
"The international community will continue to use diplomatic and humanitarian support to achieve long-term stability, avoid civil war, economic collapse and a deeper humanitarian crisis in Yemen,” the spokeswoman added.