Germany's Defence Minister Ursula von der Leyen on Friday warned Washington, DC, against hurting European cohesion and seeking a rapprochement with Russia behind the backs of its allies.

Europe has been rattled by President Donald Trump's praise for Britain's decision to quit the EU, his criticism of NATO, and his softer approach toward Russia.

'Our American friends know well that your tone on Europe and NATO has a direct impact on the cohesion of our continent,' the German minister told the Munich Security Conference.

'A stable European Union is also in America's interest, as is a strong and unified NATO,' she said.

Germany's Defence Minister Ursula von der Leyen said on Friday that a 'stable European Union is also in America's interest' and so is a 'strong and unified NATO'

Europe has been rattled by President Donald Trump's praise for Britain's decision to quit the EU, his criticism of NATO, and his softer approach toward Russia

She also cautioned the United States against taking transatlantic ties for granted, pointing out that it should not put its allies and Russia on the same footing.

'There cannot be a policy of equidistance to allies and to those who openly question our values, our borders and international law,' she said.

While pursuing a reliable relationship with Russia as a whole, allied nations must not be 'going above partners' heads in bilateral negotiations', she added.

Since taking office Trump has said he fully backs NATO, but he spoke with disdain about the alliance while campaigning for election, calling it 'obsolete'.

He has repeatedly praised Putin and called for better cooperation with Russia, including in the fight against the Islamic State group in Syria.

Germany signed a series of agreements with its NATO partners to jointly buy transport aircraft and submarines and develop new weapons.

Details of the agreements seen by The Associated Press Thursday show Germany aims to buy eight Airbus A330 transport planes along with the Netherlands and Luxembourg if Norway and Belgium also sign up.

NATO allies have long struggled to find enough transport planes to deploy troops and equipment.

Von der Leyen also cautioned the United States against taking transatlantic ties for granted, pointing out that it should not put its allies and Russia on the same footing. Pictured above is Russian President Vladimir Putin

Germany and Norway plan to buy six submarines together and replace their aging missile systems.

Berlin will also work together with France to set up a smaller air transport unit aimed at supporting special operations and for helping German nationals in trouble abroad.

Von der Leyen also took aim at Trump's move to ban migrants from majority-Muslim nations.

Although the initial decree to block people from seven mainly Muslim nations from entering the United States was scrapped as it fell foul of the law, Trump has said he is considering drafting a new order.

'We should be careful that this fight (against terror) does not become a front against Islam and Muslims,' said von der Leyen.

'Otherwise we run the risk of digging ourselves into a deeper grave in which violence and terror only grow further. Rather, it is right to seek partnership with like-minded Muslim and Arab nations,' she said.