Martens and his colleague Frank Henkel are visiting Zagreb to collect information on Croatia's preparedness for EU accession and prepare a report for the relevant Bundestag committees before it ratifies Croatia's accession treaty.
In parliament, Martens and Henkel were received by Speaker Josip Leko, among others.
Asked about speculation on post-accession monitoring, Martens said that only one German MP said it was necessary but that no body of the German government or parliament was considering this possibility for Croatia.
Following bad experiences with previous enlargement rounds, Croatia was asked to meet all requirements before accession, he said.
Croatian MPs informed the German commissioners that the Klek and Zaton Doli border crossings will be completed by July 1, that 413 border police were hired in 2012 and that another 100 will be hired this year.
The remaining border crossings will be finished before Croatia's EU accession on July 1, and the incumbent government would like Croatia to meet all the requirements for the Schengen area during its term, the Croatian MPs said.
Martens and Henkel were also briefed about the judicial reform, and were interested in citizen's mood regarding the EU and how the parliamentary committees see Croatia's economic prospects after joining.