The talks were held at a lunch given by the German president.
Mesic later told the press that the talks addressed Croatia's EU entry talks, launched on October 3, the situation in the region with an emphasis on Serbia-Montenegro and Kosovo, and the overall situation in Europe, notably the difficulties the EU found itself in after the European constitution was rejected by French and Dutch referendums.
The talks focused on Croatian-German relations. Mesic thanked Koehler for the fact that Germany "recognised from the very start the new reality in the former Yugoslavia," and for Germany's recognition of Croatia as an independent state and support in the adoption of standards.
Mesic said Croatia and Germany shared the same views on Bosnia-Herzegovina. "It transpired from the talks that we share identical views that BH should become compatible with the EU," he said and underlined the need to upgrade the Dayton agreement, which ended the war in Bosnia 10 years ago, also because of Bosnia's goal to join the EU.
The Croatian president said he and Koehler also shared the views on Serbia-Montenegro and Kosovo.
Asked by the press if Koehler had made any recommendations regarding Croatia's EU negotiations, Mesic said they talked about how Germany would help.
"Croatia doesn't need humanitarian aid but partners. Croatia is a country of opportunity in which it is worth to invest," he said and expressed regret that Koehler was unable to attend a recent meeting of Central European presidents in Zagreb because of difficulties in forming a new government.
"I officially invited him to visit Croatia soon and he was pleased to accept the invitation," said Mesic, who is on a two-day visit to Berlin.
Later today he is scheduled to attend the opening of an exhibition on archaeological sites in Istria.
On Saturday Mesic will give a talk on European identity from the perspective of Southeast Europe as part of a forum organised by the BMW Herbert Quandt foundation.
He will wrap up his visit tomorrow afternoon by visiting the Holocaust Victims Museum.