HELSINKI, May 25 (Xinhua) -- German Foreign Minister Heiko Maas said here on Friday that he was cautiously optimistic about finding a solution to the trade disputes between the EU and the U.S.

At a joint press conference with Finnish Foreign Minister Timo Soini, Maas said "It cannot be so that free trade is being reduced step by step", adding that it is difficult to negotiate under threats.

Soini said Finland and Germany are both strong supporters of free trade.

There is still some time left, but it will not be easy to reach a solution on the trade issue, said the Finnish minister.

The United States has temporarily exempted the EU from heavier tariffs on steel and aluminum exported to the U.S. But the exemption will expire early June.

U.S. President Donald Trump said on Wednesday he had asked for an investigation into automobile imports under Section 232 of 1962 Trade Expansion Act, which would allow increased tariffs on national security ground.

European Commission Vice-President Jyrki Katainen said on Thursday that the action was "difficult to understand".

Relations between Finland and Germany were also highlighted in Helsinki on Friday. Maas appeared as the main speaker in the celebration of the 100th anniversary of the Finnish Foreign Ministry and had talks with Finnish President Sauli Niinisto.

Maas underlined the shared values of the two countries as the basis for relationship. "And they share the view of keeping Europe united and making it stronger and more endurable in crisis."

Maas also stressed the need for the European Union to be united and maintain cohesion.

Commentators here have noted the role of Germany as a companion to Finland will increase after Britain's likely exit from the EU.