WASHINGTON (Reuters) - President Donald Trump will drill down on Russia’s “malign activity” during summits with NATO allies and President Vladimir Putin, U.S. officials said on Thursday, signaling a harder line against Moscow than Trump has traditionally taken.

The U.S. president, whose 2016 election campaign is being probed for possible collusion with Russia, has said repeatedly he wants to have a good relationship with Washington’s former Cold War foe, despite tensions between Russia and the West over Ukraine, Syria and alleged election meddling around the world.

Trump, who is set to leave for Europe on Tuesday, will hold meetings with NATO allies in Brussels, visit Britain, and then meet Putin in Helsinki for a one-on-one meeting on July 16.

“The president believes a better relationship with Russia would be good for both America and Russia, but the ball really is in Russia’s court and the president will continue to hold Russia accountable for its malign activity,” Jon Huntsman, U.S. ambassador to Russia, told reporters on a conference call.

“We’re entering with our eyes wide open, but peace is always worth the effort,” Huntsman said.

Trump told reporters last week he would press Putin on election meddling and also discuss Syria and Ukraine during their meeting.

A Senate Intelligence Committee report released on Tuesday supported the conclusion of three U.S. intelligence agencies that Russia tried to help Donald Trump win the 2016 U.S. presidential election.

FILE PHOTO: Russia's President Vladimir Putin talks to U.S. President Donald Trump during their bilateral meeting at the G20 summit in Hamburg, Germany, July 7, 2017. REUTERS/Carlos Barria//File Photo

Trump has denied that his campaign colluded with Russia and has repeated that Putin has denied involvement in the U.S. electoral process.

European allies are also concerned about election meddling by Russia. But the North Atlantic Treaty Organization (NATO) summit is likely to be dominated by Trump’s insistence that member nations step up and pay more for their joint defense.

Kay Bailey Hutchison, the U.S. permanent representative to NATO, said Russia would be a key topic at the summit.

“I would say our (NATO’s) major areas of deterrence would be Russia and the malign activities of Russia, the efforts of Russia to divide our democratic nations, INF (Intermediate-Range Nuclear Forces) Treaty violations,” she said.

Trump and Putin will likely also discuss two arms control pacts - the INF Treaty and the New Strategic Arms Reduction Treaty (New START), Huntsman said, declining to address whether they might strike a deal on either pact, which are planks of U.S.-Russian arms control.

The INF Treaty, signed by the United States and the Soviet Union in 1987, required both sides to eliminate their ground-launched ballistic and cruise missiles with ranges between 500 and 5,500 km (310 and 3,420 miles).

Each side accuses the other of violating the treaty, which applies to nuclear- and conventionally armed missiles. The two sides, which deny violating the pact, have made no obvious progress on resolving the dispute.

The leaders are also likely to discuss New START, under which both nations cut their deployed strategic nuclear warheads to no more than 1,550, the lowest level in decades. The treaty, signed during the Obama administration, also limits deployed land- and submarine-based missiles and nuclear-capable bombers.

The treaty, which expires in February 2021, can be extended by five years if both sides agree.

“My guess is that that will be part of the discussion as well, but I don’t want to get ahead of the possible summit conversations,” Huntsman said.