A diplomatic row over comparing Hungary’s bid to boost its birth rate with Nazi Germany has intensified.

Prime Minister Viktor Orban announced tax and loan benefits earlier this month to increase the number of Hungarian children.

Orban, a right-wing nationalist, claimed the country needed Hungarian children rather than immigrants.

It later prompted Swedish minister Annika Strandhall to compare the policy to Germany in the 1930s.

"What is happening in Hungary is alarming. Now, Orban wants more 'genuine' Hungarian children to be born," the social affairs minister tweeted.

“This policy reeks of the 30s and as right-wing populists, they need to create smoke-screens for what this kind of politics does to the independence that women have been fighting for.”

On Wednesday, Sweden and Hungary complained to each other’s ambassadors over the controversy.

It comes after Zsolt Semjen, Hungary’s deputy prime minister, said Strandhall's remarks were an aberration triggered by political correctness.

Sweden’s ministry of foreign affairs summoned Hungary’s ambassador to warn against making personal attacks.

Budapest meanwhile spoke to Sweden’s ambassador and said it was appalling to accuse the Hungarian government of Nazism over its efforts to help families.

Hungary’s fertility rate was 1.53 children per woman in 2016, the highest level for more than two decades, according to the latest data from Eurostat.

But it is still below the EU-wide average of 1.6.

Sweden’s, meanwhile, was 1.85 in 2016, the lowest it’s been for 10 years.