President Macron, HRH Crown Prince co-chaired the first meeting of the Saudi-French Strategic Partnership Council, which was attended by a number of ministers and senior officials of the two governments.
"Under various pretexts, demands and foreign or domestic pressure, Saudi Arabia presses ahead with its policy to purchase security and weapons, justifies its failed or defeated projects in war on Yemen and forms an alignment with the occupying regime of Israel as one of the main regional criminals and destabilisers". Human rights groups also question how far the kingdom has come.
"If required by our alliance with our partners, we will be there", he said, according to the French translation of his remarks spoken in Arabic.
Macron is only eight years older than the prince.
A Yemeni rights group on Tuesday filed a lawsuit against Prince Mohammed in France, accusing him of complicity in torture and inhumane treatment in Yemen, lawyers said.
"Since the start of the conflict in Yemen, France has adopted a very specific process whereby all sales of military equipment are analysed on a case-by-case basis and on the basis of reinforced criteria that reflect respect for worldwide humanitarian law and the risk of harm to civilian populations", Macron said.
He also said the two sides agreed on the necessity to respond to the chemical attack on the Syrian city of Douma, in addition to the need to "reduce Iran's ballistic activities and expansionism in the region".
They signed a cooperation agreement on research and tourism at the Mada'in Saleh archaeological site in northwest Saudi Arabia.
President Emmanuel Macron and Prince Mohammed bin Salman touring the Louvre museum. Cospedal was representing Spanish Foreign Minister Alfonso Dastis who is accompanying Prime Minister Mariano Rajoy on an official visit to Argentina.
But the trip follows a period of underlying tensions.
Saudi national oil company Aramco and French oil giant Total also announced a deal worth $9bn that would see the construction of a petrochemical complex in Jubail, Saudi Arabia.