VIENNA — At least four countries Friday firmly rejected a European Union plan to impose refugee quotas to ease a worsening migrant crisis that Germany’s foreign minister said was “probably the biggest challenge” in the history of the 28-nation bloc.

Hungary, which along with the Czech Republic, Slovakia and Poland said it would not support the proposal, threatened instead to crack down on the thousands of people streaming across its borders daily as they flee war and persecution.

The stance by those Central European countries reflected a hardening front against distributing at least some of the refugees among them and was a stinging rebuff to German Foreign Minister Frank-Walter Steinmeier, who traveled to Prague to try to persuade them to reconsider.

While the Czechs, Slovaks and Poles have been relatively unaffected by the influx, Hungary has faced growing criticism about its stance toward the asylum seekers.

Other EU leaders and human rights groups accuse the government of gross mismanagement or serious negligence in housing, feeding and processing the migrants traveling from the Balkans and through Hungary to Western Europe.

– The Associated Press