Denmark will implement temporary controls at the German border, Prime Minister Lars Løkke Rasmussen announced at a press conference on Monday.
The new controls took effect at 12pm and will initially last for ten days. After that time, the border controls can be extended by 20 days at a time as the situation warrants, the PM said.
Rasmussen made the announcement just 12 hours after Sweden began checking the identification of all arrivals from Denmark and the PM said that the move was "a reaction to a decision made in Sweden".
"This is a major step and it should be seen in light of the serious migration and refugee crisis that Europe is facing. [It is] likely the biggest and most complicated crisis we have seen this century," Rasmussen said.
The border controls at the German border will not be a "one to one" copy of Sweden's model in which private transport companies are tasked with checking the identification of all passengers. Instead, Danish police will carry out random checks on ferries and trains arriving from Germany.
"Not everyone from Germany will be checked. The police will not ask everyone to show their passports," Rasmussen said.
The PM said he informed German Chancellor Angela Merkel of his decision earlier on Monday.
"This could negatively affect the good communal life in the German-Danish border region and especially be a burden on commuters."
Rasmussen said that Denmark wants to avoid the "chaos" and "serious disruptions" created by Sweden's border controls, which are expected to cause significant delays for the roughly 8,600 daily commuters between Copenhagen and the southern Swedish city of Malmö.
The Danish PM characterized his decision as a direct result of policies put in place not only by Sweden but Norway and Finland as well, and said that other European countries were likely to follow suit.
"It's pretty obvious that if the European Union can't protect its external borders, you will see more and more countries forced into introducing internal border controls," Rasmussen said, adding that Denmark's decision was "not a happy moment".