Mr Koizumi visited the Checkpoint Charlie museum in Berlin

Discussions were expected to focus on the North Korean nuclear crisis, the reconstruction of Iraq and the enlargement of the European Union.

From Germany, he will head to Poland and the Czech Republic - both of which are due to join the EU next year.

Japanese officials said Mr Koizumi would discuss North Korea with Mr Schroeder, as Germany has diplomatic ties with the Stalinist state.

The crisis over North Korea began last October when US officials said Pyongyang had admitted to having a secret nuclear weapons programme in breach of a 1994 agreement.

Mr Koizumi said Germany and Japan could learn from each other's economic problems.

"Germany suffers from similar problems to Japan; a weak economy, falling stock prices, troubled loans and a progressive aging of society," Die Welt newspaper quoted him as saying.

Opera fans

After their meeting in Berlin, Mr Koizumi and Mr Schroeder plan to fly to the southern town of Bayreuth for a performance of the opera, Tannhauser, at the annual Wagner Festival.

The Japanese prime minister arrived in Berlin on Sunday afternoon, and visited the Checkpoint Charlie museum, site of a famous Cold War checkpoint that divided East and West Berlin.

On Tuesday he will meet the Polish Prime Minister, Leszek Miller, and on Thursday he is due to hold talks in Prague with Czech Prime Minister Vladimir Spidla.