The world's smallest monkey is at the center of a Swedish-Saudi diplomatic spat

Saudi Arabia has blocked the transfer of four monkeys to a zoo in Riyadh from Sweden because of its diplomatic spat with Stockholm, the Swedish zoo where they were bred said on Thursday.

Jonas Wahlstrom, head of the Skansen Zoo, said he had received a call from Riyadh Zoo saying that Saudi authorities would not grant entry to the pygmy marmosets.

"They didn't want the monkeys anymore because of the political situation," Wahlstrom reportedly told the BBC.

Skansen sends around 10 pygmy marmosets a year from its breeding program to zoos around the world.

The pygmy marmoset weighs approximately 3.5 ounces and measures less than 5 inches in length, making it the smallest monkey in the world.

In mid-March, Saudi Arabia withdrew its ambassador to Sweden over criticism of the kingdom's human rights record and after Stockholm ended a long-standing defense cooperation agreement with Riyadh.

Saudi Arabia has since decided to send its envoy back to Sweden, but relations have yet to return to normal. Skansen hopes the spat will be resolved soon to the monkeys can go to Riyadh.

"Otherwise, we will send them somewhere else," Wahlstrom said.

Here's another look at the monkey:

And here's some background on the monkey:

(Reporting by Johan Sennero; Editing by Raissa Kasolowsky)