US President Donald Trump has said the July 16 meeting with his Russian counterpart Vladimir Putin in Helsinki could be the easiest stop on his European tour, during which he will also meet America's historic allies. "So I have NATO, I have the UK, which is in somewhat turmoil, and I have Putin. Frankly, Putin may be the easiest of them all. Who would think? Who would think?" Trump said on Tuesday just before boarding the presidential aircraft Air Force One for his flight to Brussels, Efe news reported. Trump arrives on Tuesday night in Brussels to take part in a two-day NATO summit before heading to the UK, and will wrap up his trip on July 16 when he meets with the Russian President in Helsinki. Asked whether Putin is a friend or enemy, Trump replied the Russian President is "a competitor". The meeting in Helsinki will be the first bilateral summit of the leaders of the two great powers, and will take place amid tensions between Moscow and Washington. "I think that getting along with Russia, getting along with China, getting along with others is a good thing, not a bad thing," Trump added before leaving for Europe. On his trip, Trump must strike a balance between promoting a thaw with Russia and not undermining relations with America's NATO allies, in an atmosphere of US-EU tension over trade. He will also visit the UK at a time when the government of Prime Minister Theresa May faces another political crisis following the resignation of two of her principal ministers, both critics of her Brexit plan to negotiate a smooth withdrawal from the European Union. In that regard, Trump spoke about one of the ministers who resigned, and who until this Monday was the UK's Foreign Minister, Boris Johnson, whom he called "a friend". "Boris Johnson is a friend of mine. He's been very, very nice to me and very supportive. And maybe we'll speak to him when I get over there," he said. "It's going to be an interesting time in the UK, and it's certainly going to be an interesting time with NATO. But we will work it out, and all countries will be happy," Trump said.