German Foreign Minister Heiko Maas is sworn-in by Parliament President Wolfgang Schaeuble in Germany's lower house of parliament Bundestag in Berlin, Germany, March 14, 2018. REUTERS/Kai Pfaffenbach

BERLIN (Reuters) - Germany’s new Foreign Minister Heiko Maas called on Russia to cooperate in the investigation into a nerve agent attack on an ex-Russian spy in England for which British Prime Minister Theresa May blames Moscow.

“We take the assessment of the British government seriously and it is disappointing that Russia seems not to be willing to contribute to clearing up (this case),” Maas said in his first speech as minister before heading to Paris.

“Moscow should be ready to be transparent .. And it is clear this cannot go without consequences,” said Maas, adding Berlin would remain in close contact with the British government.