German Chancellor Angela Merkel met with Croatian Democratic Union (HDZ) leader Tomislav Karamarko in Ruesselsheim, near Frankfurt, on Tuesday, Croatia's strongest opposition party said on its website.
The HDZ said that its delegation, also including secretary-general Milijan Brkic and head of the party's coordinating body for Germany Franjo Akmadza, had been invited to attend as a guest the CDU's campaign for forthcoming parliamentary elections.
Both parties are members of the centre-right Christian Democratic group, the European People's Party (EPP).
The meeting took place after Chancellor Merkel, who is also the CDU president, attended the party's election rally in Ruesselsheim, in the federal state of Hessen, the HDZ said.