Romania and Bulgaria, which joined the EU in 2007, are obliged to join the area - but the process has been delayed pending the completion of other obligations like tackling corruption and organized crime.
EU interior and justice ministers meet in Brussels on Thursday with this issue on the agenda.
"Should Romania and Bulgaria insist upon a vote [at the meeting], then the proposal will fail by virtue of a German veto," Friedrich told Spiegel. " Even the possibility of partial approval - for arrival by air, or seaports - is off the table."
Friedrich said that both countries still had work to do on the other preconditions for Schengen membership, saying this was why Germany would block an eventual motion at the present time.
He also sought to ward off warnings of economic migration from two of the EU's poorest members.
"The right to freedom of movement means that every EU citizen can live in every member state, if they are working or studying there. Any EU citizen who fulfills these criteria is welcome here," Friedrich said. "But whoever is only coming to cash in on state benefits, and is therefore abusing this freedom of movement, needs to be meaningfully prevented."
Side-swipe at the Commission
The interior minister, a member of the Bavarian CSU, sister party to Chancellor Angela Merkel's Christian Democratic Union, said this could be achieved with progress on two fronts: better use of EU development funds by governments in countries like Romania or Bulgaria, and stricter punishments for people found traveling abroad to claim social welfare.
Friedrich said he would be pushing for punitive measures like a one-year ban on people returning to a country after they were sent home on such grounds.
"The European Commission will have to learn to pay closer attention to the points of view and sensibilities of people within the member states," Friedrich said, when asked whether the suggestion might be poorly received in Brussels. "This fundamental position of 'we'll turn a blind eye here, the main thing is that the EU continues to grow' is no longer acceptable from individuals who have a responsibility towards European citizens."
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