U.S. President Donald Trump walks prior to the EU-USA Leaders' Meeting at the European Council headquarters, in Brussels, Belgium, May 25, 2017. (Xinhua/Thierry Monasse)

WASHINGTON, May 30 (Xinhua) -- U.S. President Donald Trump on Tuesday called Germany's trade and military spending policies "very bad" for the United States as tensions between him and German Chancellor Angela Merkel increased.

"We have a MASSIVE trade deficit with Germany, plus they pay FAR LESS than they should on NATO & military," Trump wrote on Twitter. "Very bad for U.S. This will change."

The blast came two days after Merkel cast doubts on EU's alignment with the United States and Britain, saying that Europeans should determine their own destiny.

Merkel, addressing a election campaign at a beer tent in Germany's southern state of Bavaria, said on Sunday that following the election of Trump and Brexit, Europeans "really have to take destiny into their own hands."

"The times when we could fully rely on others are to some extent over." Merkel said.

Although Merkel did not further elaborate the reasons for her unexpected remarks, many German media speculated that Merkel was referring to her frustrating experience at the G7 meeting earlier this week in Italy's Sicily.

The German leader described the summit as "very difficult, not to say very unsatisfactory."

Trump and Merkel had a long history of disagreement that was previously focused on the two leaders' view on immigration.

During his campaign and also after winning the presidency, Trump repeatedly blasted Merkel for making a "catastrophic mistake" with her open door policy on refugees, while Merkel did not shy away from criticizing Trump in the wake of his travel ban order that sought to temporarily ban travellers from seven Muslim-majority countries in January.