International anger over US government surveillance has combined with a backlash against its current Middle East policy to leave President Obama increasingly isolated from many of his key foreign allies, according to diplomats in Washington.

The furious call that German chancellor Angela Merkel made to the White House on Wednesday to ask if her phone had been tapped was the latest in a string of diplomatic rebukes by allies including France, Brazil and Mexico, all of which have distanced themselves from the US following revelations of spying by the National Security Agency.

But the collapse in trust of the US among its European and South American partners has been matched by an equally rapid deterioration in its relationships with key allies in the Middle East.

Saudi Arabia this week joined Israel, Jordan and United Arab Emirates in signalling a shift in its relations with the US over its unhappiness at a perceived policy of rapprochement toward Iran and Syria.

Though the issues are largely unrelated, they have led to a flurry of diplomatic activity from Washington, which is anxious to avoid a more permanent rift in the network of alliances that has been central to its foreign policy since the second world war.

Secretary of state John Kerry has been meeting with Saudi and Israeli leaders in an effort to keep them involved in Middle East peace talks about Palestine and Syria, Obama met Wednesday with Pakistani prime minister Nawaz Sharif to reassure him over separate anxiety over US drone attacks, and the White House has been privately trying to mend fences with world leaders on the surveillance issue.

"The [NSA] revelations have clearly caused tension in our relationships with some countries and we are dealing with that through diplomatic channels," said White House spokesman Jay Carney on Thursday.

"These are very important relations both economically and for our security, and we will work to maintain the closest possible ties."

But the Guardian has spoken with several diplomats and foreign government officials – all of whom agreed to talk only on the condition of anonymity – who say the White House is still underestimating the anger felt over recent disclosures.

They argue that US officials are being deliberately disingenuous when they claim that all countries engage in similar forms of espionage, even against allies. While it is widely accepted that the US, Britain, France, Russia and China engage in counter-espionage, other countries do not have the tools to conduct surveillance on the scale of the NSA.

Obama, Merkel and Hollande at the G20 summit in St Petersburg. Photograph: Getty

A European diplomat said that the White House had presented a false comparison by claiming all countries were engaged in the same tactics.

"How would the US respond if it discovered a friendly country was covertly listening to the calls of thousands of US citizens – including Obama?" the diplomat said.

France, Mexico, Brazil and Germany have all provided the White House with a list of detailed questions about the reports of surveillance, demanding explanations and assurances it will stop. None have so far received what they believe to be a satisfactory answer.

Some foreign officials posted in Washington have changed the way they conduct business since the revelations about US surveillance: not speaking about sensitive information over the phone, increasing the frequency of de-bugging inspections in embassies, and keeping some communications – those deemed most secret – out of secure cables, having now concluded that their encryption may have been compromised by the NSA.

In Brazil, thousands of federal workers are now being ordered to adopt a form of highly-encrypted email – a program that was quickly accelerated after the Edward Snowden disclosures. And although the State Department insists that a planned bilateral meeting between Obama and Brazillian president Dilma Rousseff has merely been "postponed", it has not yet been rescheduled. Brazil is insisting the US come clean about the nature of the surveillance it has been conducting before it schedules another summit.

Speaking before Wednesday's revelation about Merkel's phone, a senior western diplomat speculated that the tenor of debate would be transformed if it emerged that an elected European politician had been targeted – as occurred in Brazil and Mexico.

"If that happened, there would be a huge uproar," the diplomat said. "This is not an issue that will go away.

"The surveillance debate in the US is focused on the constitution – and whether the privacy of US citizens is compromised. There seems to be minimal acknowledgement about the concern other countries have about the rights of their citizens."

One European official said the disclosures had prompted EU countries to review policies on internet governance, privacy and data-sharing, amid growing scepticism about whether the US can be trusted. Major transatlantic trade negotiations have also been jeopardised amid anxiety that the US' surveillance tools give it an advantage during talks.

"It has become clear we're not doing business on a level-playing field during negotiations," the official said.

A Brazilian official said that some top-level discussions with the US on energy matters had been suspended as a consequence of leaks, which suggested Canada may have spied on its energy and mines ministry. It would be "impossible" for discussions to proceed on that basis, the official added.

A Latin American diplomat said that if no satisfactory answer and apology was forthcoming, a scenario they thought unlikely, there would be enormous pressure for affected countries to react with more than just rhetoric.

"Countries that have close partnerships simply should not spy on each other to that kind of level," they said. "There has to be some kind of consequences."

The combination of diplomatic setbacks has led to particular scorn from Obama's critics on the American right, who compare his growing international unpopularity with his criticism of George W Bush for damaging America's reputation through the Iraq war.

"This is a perfect storm," said Jim Carafano of the Heritage Foundation, a conservative think-tank. "Countries are getting impatient with US foreign policy largely because they see it as one of disengagement, but the NSA scandal has given them fresh reason to mistrust us, too."

So far the official response in Washington has been muted, but there are signs of growing American frustration with the criticism it is receiving at the same time that it is expected to act as world leader.

On Wednesday, for example, Washington's outgoing ambassador to Saudi Arabia, James Smith, rebuked those calling for greater US involvement in the Middle East.

"Much criticism has been directed at the US and there is a mounting frustration at the perceived lack of a coherent foreign policy in the region but then we hear the same refrain that somehow only we can fix it," he told an Arab/US policy conference in Washington.