Candidate Trump said he might ease the embargo without getting anything in return.
"Allies should invest more in defense not to please the United States but because it is in their own interest," NATO's Jens Stoltenberg said.
The U.S. and Russian militaries have found themselves increasingly at odds in the world.
A center of excellence on hybrid warfare should be sited in Ukraine.
Putin's Russia heads the list of likely suspects.
The top U.S. Army commander in Europe complained that Russia is being too secretive about upcoming large-scale military drills.
A Russian jet tried to intimidate a NATO jet while attempting to escort the Russian defense minister's plane in international airspace, state news agencies claim.
A Russian fighter jet reportedly buzzed a U.S. reconnaissance plane near the Baltic Sea, hours after the U.S. shot down a drone in Syria.
It is a busy summer for Russia and allied forces around the Baltic Sea.
The fallout of Trump's disregard for the 70-year-long military alliance is offering Vladimir Putin an opportunity, according to a top ex-diplomat.
The border between Poland and Lithuania is strategically important because its seizure would cut off the Baltic states from the rest of the Western alliance.
McMaster, Tillerson, Mattis, and Kelly have largely ruined their own credibility.
A crowd of Russian aircraft, including Tu-160 supersonic bombers, had three air forces tracking them.
The U.S. is finishing up naval exercises with NATO allies in the Baltic region, but Russia has an even bigger display of military might in the works.
Trump's opposition could give House Republicans cold feet about voting on the bill.
The Russian leader complained of encirclement by Western powers and said Moscow can and will strike back in the case of any foreign attack.
The Baltic country claims Russian jets and vessels neared its borders 13 times last month.
The Baltics have been particularly worried about Russia's annexation of Crimea in 2014.
Around half of En Marche's candidates are political newcomers, with the average age under 50.
Jean-Claude Juncker has called for the EU to collaborate more on defense projects.
'For too long we have relied too much on the military power of others,' European Commission President Jean-Claude Juncker said. 'We must now seize the moment to take charge of our own security.'
"NATO is a mere instrument of U.S. foreign policy," the Russian president added.
Canada's military looks set to get a financial boost as its foreign minister says the U.S. is seeking to "shrug off" burden of world leadership.
Putin's spokesman said Moscow wants to hear Trump's opinion after his deputy accused Russia of "efforts to redraw international borders by force."