Before his visit, the 32-year-old Crown Prince Mohammed had emphasised the importance of the relationship between the United Kingdom and Saudi Arabia regarding security.
The crown prince, who is heir to his 82-year-old father, King Salman, said there were "huge opportunities" to boost trade between the two countries and they had to work together to deal with "failed states. terrorist and extremist organisations" in the Middle East.
Yemen has been since March 2015 under a brutal aggression by Saudi-led coalition, in a bid to restore power to fugitive former president Abdrabbuh Mansour Hadi.
Saudi Crown Prince reviewed with the UK Defense Secretary Gavin Williamson the means of strategic cooperation and developing defense, military and anti-terrorism efforts, on Friday, at the North Holt Air Base.
Bin Salman, who was in London from Wednesday until Friday, is regarded as the architect of Riyadh's three-year war on Yemen.
Windows 10's next update will be called 'Spring Creators Update'
It's been a while since Microsoft released a new Windows 10 build to the Slow ring, but today, the company released build 17115. Recall, it will replace the Windows 10 S and will offer the same functionality but without the need to reinstall the system.
May defended the Saudi bombing campaign in Yemen suggesting "their involvement ... came at the request of the legitimate government of Yemen, it is backed by the United Nations Security Council and as such we support it", she said. About 200 had lined up outside the gates of 10 Downing Street on Wednesday to greet the Saudi leader.
The war is being led by bin Salman, also Saudi Arabia's defense minister, with the help of the USA and the UK.
The British prime minister was expected to address the humanitarian issues of the Yemen war with the Saudi crown prince at a private dinner inside her country residence on Thursday.
Germany earlier this year halted arms sales to the parties involved in the Yemen conflict, prompting Saudi Arabia to say it would find weapons elsewhere. The military equipment sold to the kingdom ever since, including warplanes, precision-guided bombs, and missiles, are worth more than $6.4 billion. More than 13,600 people have died since the onset of the war and the impoverished country has turned into the scene of the world's worst humanitarian crisis, according the UN.