President Donald Trump's recent trip to Europe is under a great deal of scrutiny after he clashed with key allies and had a controversial meeting with Russian President Vladimir Putin.

In this context, many are concerned Trump is doing immense damage to America's global standing.

A majority of Americans (61%) feel the US is less respected across the globe with Trump in the White House, according to an NBC News/SurveyMonkey poll released Wednesday.

Experts warn it could take "years" for the world to trust the US again as Trump continues to attack the international institutions it played a fundamental role in building following World War II.

President Donald Trump returned from a trip to Europe this week in which he insulted key US allies and caused a crisis at a NATO summit in Brussels, was met with nationwide protests in the UK, and sided with Russian President Vladimir Putin over the US intelligence community on the subject of election interference during a now infamous press conference in Helsinki.

Once back in the US, Trump on Tuesday walked back on his statements regarding Russian election meddling, stating he believed the conclusion from US intelligence agencies that the Kremlin interfered in the US presidential election, though he also said it could be "other people also."

But on Wednesday, Trump claimed Russia is not planning future attacks on US elections, directly contradicting statements made by Director of National Intelligence Dan Coats earlier this week.

Americans think Trump is ruining their country's reputation

In this context, many are concerned Trump is doing immense damage to America's global standing by pushing away allies and taking the word of foreign adversaries over US intelligence agencies.

A majority of Americans (61%) feel the US is less respected across the globe with Trump in the White House, according to an NBC News/SurveyMonkey poll released Wednesday.

Meanwhile, experts warn it could take "years" for the world to trust the US again as Trump continues to attack the international institutions it played a fundamental role in building following World War II, especially the NATO alliance and the United Nations.

'It will take a long time for the world to trust US stability again'

David Rothkopf, a foreign policy expert and visiting scholar at the Carnegie Endowment for International Peace, warned against hyperbolic assessments of the impact Trump can have on America's place in the world.

"Nothing is irrevocable," Rothkopf told Business Insider. "Much of America's global standing is based on factors that Trump won't or can't greatly diminish — from the vitality of our economy to our innovation, the strength of our armed forces to our history."

But Rothkopf also noted that Trump does have the capacity to do "long-term damage to our alliances, our crucial international relationships and the international system that has been essential to our peace and stability since World War II."

These relationships could recover quickly, Rothkopf said, but "underfunded institutions" may take longer to recover. What will take longest to address is the "degree to which countries like China or groups of countries like the EU take the lead in our absence."

'It will be hard to reverse the gains of dictators'

Russian President Vladimir Putin gave a soccer ball to President Donald Trump as a gift during their meeting in Helsinki. Kevin Lamarque/Reuters

Rothkopf also warned of the broader impact of Trump's tendency to cozy up to authoritarians such as Putin and his willingness to meet with North Korea's Kim Jong Un.

"It will be hard to reverse the gains of dictators and opportunists who take advantage of Trump policies to extend their influence," Rothkopf said. "And it will take a long time for the world to trust US stability again ... several election cycles for them to tell whether Trump was an aberration or just a symptom of a greater problem with America."

Célia Belin, a visiting fellow in the Center on the United States and Europe at the Brookings Institution, expressed similar sentiments.

"No damage is ever irrevocable when it comes to global standing, but it could take years to repair," Belin told Business Insider, adding that the US is becoming an "unreliable and untrustworthy actor" under Trump.

Trump has routinely made misleading claims about the way in which NATO functions and financial commitments member states have made, sometimes incorrectly suggesting other member states owe money to the US for protection.

NATO was established upon the notion of collective defense, outlined in Article 5 of the alliance's founding treaty. But Trump has even called into question whether the US would honor Article 5 under his leadership, suggesting he would be reluctant to deploy the US military to come to the defense of other member states.

Concurrently, critics of Trump have blasted him for UN-related decisions such as pulling out of the landmark Paris climate accord.

As Trump pushes traditional allies away, nations will become "increasingly reluctant" to view it as a reliable partner, Belin said, adding, "Allies and partners will now refuse to trust America blindly."

"Trump's damage to US standing will be depend on how long he stays in power, and on how other nations rebalance and diversify away from the US," Belin said.

'We will regress and spend lots of time trying to recover'

Brandon Valeriano, the Donald Bren chair of armed politics at Marine Corps University, agrees Trump's impact on America's global standing will likely be "temporary" for the most part. But he said the next administration will have its work cut out for it because of Trump in terms of "resetting and restoring" the global order.

"Put simply, we will regress and spend lots of time trying to recover," Valeriano told Business Insider.

Heather Conley, director of the Europe Program at the Center for Strategic and International Studies, said the transatlantic alliance the US helped build post-World War II was on a "slow yet steady slide" when Trump entered the White House, but added that he has "put a heavy foot on the accelerator to hasten its decline."

Conley said part of the problem is there is no general consensus in the US for what its role in the world should be moving forward.

Accordingly, Conley said the US needs to "repurpose" the transatlantic alliance for a "new generation of Americans and Europeans in the 21st century before it is too late," warning the trends of "isolationism, nativism and anti-Semitism" are currently testing America's relationship with its traditional allies in a deeply unsettling way.

'We elected someone who devalues and denigrates our core allies and partners'

President Donald Trump at the NATO summit in Brussels. Reuters/Francois Lenoir

Daniel Nexon, an associate professor in the School of Foreign Service and the Department of Government at Georgetown University, said Americans should be "extremely worried" about Trump's approach to foreign policy if they truly "care about the core infrastructure of American international leadership."

Nexon told Business Insider it's too soon to determine whether Trump has done permanent damage to America's global standing, but said that in electing him as president, the US essentially demonstrated it's not capable of choosing "competent" leaders. This sends a troubling message to the wider world and erodes trust in the US as a world power, Nexon said.

"We elected someone who devalues and denigrates our core allies and partners. While other Republican elected officials – and some members of the administration – voice support for American allies and traditional American international values, they certainly aren't checking Trump in the way that foreign allies and partners hoped," Nexon said.

With Trump at the helm, Nexon said European and other historic US allies will begin to think, "Even even if we survive his presidency, there’s nothing to stop Americans from electing another person like him."