Germany and Britain's top security officials say they've agreed to even closer cooperation in the fight against terrorism and extremism, and to manage the challenge of the migrant flows to Europe.

British Home Secretary Amber Rudd, who took her position after the British voted this summer to leave the European Union, and German Interior Minister Thomas de Maiziere said in a joint statement provided by the British Embassy on Thursday that to fight terrorism, they would expand the exchange of intelligence information and cooperate more closely in investigations and de-radicalization measures.

They also pledged to cooperate with Greece and Turkey to ensure the functioning of the EU-Turkey agreement on migrants, and to work together to fight human smugglers and protect the EU's exterior borders.