Over 10,000 police officers and other security forces will ensure the security of the NATO summit in Madrid in late June, Spanish media reported on Friday, citing the Ministry of the Interior.
It will be "the largest security presence in [Spain's] recent history," the national broadcaster RTVE reported, adding it will turn the city into a fortress.
As well as other measures, Spain will introduce temporary border checks, as it had done for the 2019 UN climate conference, in order to guarantee the safety of the 5,000 attendees of the summit.
Around 40 delegations are expected, making up a combined total of 2,000 guests, along with around 2,000 journalists from across the world and 1,000 helpers of the organization committee.
A spokesperson for the Interior Ministry was cited as saying that, so far, authorities have not established any "particular threat that would be grounds for concern."
In reference to the ancient Greek goddess of peace, the operation is being called Operation Eirene.
The government will call on the people of Madrid to work from home if possible and to take no unnecessary trips, RTVE reported.
Madrid Mayor José Luis Martínez-Almeida has warned the population that the days of the summit will require patience.
Protests are also expected to take place, and the city will therefore be "completely blocked."
The NATO summit takes place against the background of Russia's invasion of Ukraine. According to NATO Secretary General Jens Stoltenberg, a significant strengthening of the deterrence and defence capacities of the allied forces is set to be decided in Madrid.