In an interview with the German newspaper Frankfurter Allgemeine Sonntagszeitung, Angela Merkel said EU member countries must find a common stance towards China and Russia.
The German chancellor, who is standing for re-election later this month, said: “The world has to see that member states won’t deviate from a European consensus on these issues.”
She said she hoped a solution to the migrant crisis would be found in the “not too distant future”.
The chancellor remains adamant the EU should not accept Russia’s annexation of Crimea.
She said: ‘When I hear, for example, that we should just accept Russia’s annexation of Crimea, I wonder: What would have happened if the question of the GDR was handled in that way, if people had said, ‘Well of course, Germany will stay divided, that won’t change’.”
Last week foreign ministers discussed steps to enable the EU to talk with one voice on global issues when they met in Estonia.
Mrs Merkel is hoping to win the German election later this month and become the country’s chancellor for her fourth term.
The chancellor and her main election rival Martin Schulz have called for an end to Turkey’s EU membership talks.
Mrs Merkel also took a swipe at the Turkish President Recep Tayyip Erdogan, who she claimed was allowing Turkey to move further away from Europe and its values.
She said: “What we are experiencing at the moment with German citizens in Turkish custody is serious and absolutely unacceptable.”
She has dismissed Turkey’s warning about travelling to Germany after Ankara had cautioned citizens they risk facing racism or terrorism if they go to Germany.
The chancellor has also said she is prepared to engage in diplomacy talks to end North Korea’s nuclear missile programme.
During the interview, the chancellor called for people not to stereotype member countries of the bloc.
She said: “I have always tried hard to tell people, never speak of the Greeks, the Italians and the French. Always see the individual human being.”
The German foreign minister Sigmar Gabriel gave a speech last week in Paris to remind Europeans of the importance of their unity.