Speaking from the Centre for Strategic & International Studies in Washington moments after a joint press conference with Donald Trump, the EU leader warned Brussels will be ready to defend itself from future threats coming from the US.
Mr Juncker confirmed a new deal had been signed by both leaders on Wednesday that will prevent both nations from introducing new trade tariffs until negotiations are completed.
But the European Commission President took a swipe at President Trump as he vowed Brussels will defend itself “with all legal means” available against future unfair measures aimed at the European Union.
He said: “Europe will always have its hand outstretched to the United States.
“We will always look for areas where we can work together on a mutually beneficial basis.
“But at the same time, we must take our future in our own hands.
“This means making ourselves more united and more responsible at home.
“That means defending ourselves with all legal means when we face unfair practices or have unfair measures aimed at us.
“That means making the most of opportunities with like-minded partners across the world.
“Just as we have done with Japan and Canada and as we are doing with countries in Latin America, Australia and New Zealand.
“And as we did today at the White House.”
During a joint press conference at the end of their meeting, President Trump said both sides had agreed to “work together towards zero tariffs”.
He also announced the EU had agreed to increase American exports of liquefied natural gas and soybeans to Europe.
The US and European Commission Presidents discussed the implementation of 20 percent tariffs on EU steel and aluminium introduced last month as well as Mr Trump’s threats to expand those measures to European cars.
The controversial move had left leaders throughout the bloc furious, with the European Union threatening to retaliate with heavy tariffs of its own on the US.