Spain's Foreign Minister Josep Borrell denied Monday that the country was experiencing "mass" immigration and said Europe needed "new blood" to compensate for a low birth rate.

"We're trivializing the word 'mass'," he told reporters after talks in Madrid with his Jordanian counterpart Ayman Safadi.

Close to 21,000 migrants have arrived in Spain by sea since the beginning of the year and 304 died in the attempt, the International Organization for Migration says.

The Libya-Italy Mediterranean route, which was the main one until recently, has dwindled by 80 percent while Spain has now become the main destination for migrants trying to reach Europe.

Migrants are also reaching Spain by land, with 602 managing to scramble over the double barrier between Morocco and the Spanish territory of Ceuta in North Africa last Thursday, throwing caustic quicklime, excrement and stones onto police below.

Borrell recognized that "this shocks public opinion and the disorderly nature of immigration produces fear."

But he said it was all relative, and "600 people is not massive compared to 1.3 million" Syrian refugees currently in Jordan.

"We're talking about 20,000 (migrants) so far this year for a country of more than 40 million inhabitants," the Socialist minister said.

"That's not mass migration."

Borrell also said the arrivals were under control, even if NGOs are warning that many migrant reception centers in Spain are saturated.

He suggested this could even help Europe, where many countries have a low birth rate.

"Europe's demographic evolution shows that unless we want to gradually turn into an aging continent, we need new blood, and it doesn't look like this new blood is coming from our capacity to procreate."