(CNN) President Donald Trump has expressed concern that the United States has "fallen behind" in its nuclear weapons capacity and that he would like to restore its supremacy.

In an interview with the Reuters news agency, Trump said he would prefer a world free of nuclear weapons but otherwise the United States should be "at the top of the pack."

The remarks came as Trump prepares to address the annual Conservative Political Action Conference (CPAC) on Friday. Trump takes top billing at the conference a day after his key advisers, chief strategist Steve Bannon and chief of staff Reince Priebus, appeared on the CPAC stage to discuss Trump's agenda and rail against the media.

'Top of the pack'

In the Reuters interview, conducted in the Oval Office, Trump said the US needed to revive its nuclear arsenal.

"I am the first one that would like to see ... nobody have nukes, but we're never going to fall behind any country even if it's a friendly country, we're never going to fall behind on nuclear power," he told Reuters.

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"It would be wonderful, a dream would be that no country would have nukes, but if countries are going to have nukes, we're going to be at the top of the pack."

The comments were his first on the US nuclear arsenal since taking office last month. In December -- hours after Russian President Vladimir Putin pledged to enhance his country's nuclear forces --Trump tweeted that the United States " must greatly strengthen and expand its nuclear capability until such time as the world comes to its senses regarding nukes."

Asked by Reuters if he would raise Russia's apparent breach of an arms control treaty with Putin, Trump replied: "I don't even know if they are discussing meetings right now, but if I meet, if and when we meet, I would bring it up."

Trump also dismissed the New START agreement, a key US-Russia nuclear disarmament treaty , as "a one-sided deal." The treaty came up in a phone conversation between Trump and Putin last month.

Accuses China of currency manipulation

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"I think they could solve the problem very easily, if they want to," he said of China.

Questioned about his support for the European Union, Trump said he was "totally in favor of it," adding: "I think it's wonderful if they are happy. If they are happy, I am in favor of it."

Senior Trump administration figures have been in Europe in recent days seeking to reassure longstanding US allies amid concerns over apparently contradictory messages coming from the White House.

On the 'two-state solution'

Asked if he was backing away from a two-state solution for Israel and the Palestinians, Trump replied: "I like a two-state solution but I ultimately like what the both parties like. I thought that was so plain. Some people covered it accurately, other people didn't. Very simple."

Speaking to reporters last week alongside Israeli Prime Minister Benjamin Netanyahu, Trump appeared to dump five decades of US policy on the Israeli-Palestinian conflict , saying he wouldn't insist on a two-state solution and would simply "like the one that both parties like."

Moving to issues closer to home, Trump indicated that he might back the introduction of a tax on imports from Mexico to help pay for his border wall, saying, "I certainly support a form of tax on the border because everyone else does."

He told Reuters that such a tax would affect other countries and companies more than the consumer.