Germany and four other European countries can continue carrying out border controls within the normally free-travel Schengen area for another six months, after EU governments on Thursday gave their blessing to the move.
One of the Europe's most-cherished achievements, Schengen usually allows free travel across 26 countries without the need for passports or border checks.
But several Schengen nations reintroduced internal border controls to stem migration flows after hundreds of thousands of migrants and asylum seekers overwhelmed their systems last year. Austria, Denmark, Germany, Norway and Sweden still have the checks in place.
The five countries have been allowed to continue the border controls because of what EU officials have said are "serious deficiencies" in Greece, whose border with Turkey is an external Schengen frontier.
Greece was accused of having let migrants pass through largely unchecked, meaning they could push further into Europe until other nations shut down their borders. There are still thousands of migrants stranded in Greece and countries further north.
The controls allowed to continue are on the Austrian-Hungarian, Austrian-Slovenian, German-Austrian and Danish-German borders, as well as in Danish and Norwegian ports, Swedish harbours and the Oresund rail and road bridge between Denmark and Sweden.
"Border controls should be targeted and limited in scope, frequency, location and time, to what is strictly necessary to respond to the serious threat and to safeguard public policy and internal security resulting from the secondary movements of irregular migrants," EU governments said in a statement.
The controls should also be carried out only at parts of the border where it is "necessary and proportionate."
The intra-Schengen border controls have raised concerns because they hamper the free movement of people and goods and generate economic costs. They have also fuelled speculation that Schengen may eventually break apart.
The European Union says it is determined to do away with the controls by late 2016.