WASHINGTON (REUTERS) - Frustration is mounting among leading foreign policy officials in United States President Donald Trump's administration as they chafe at some policy and bureaucratic defeats and complain they lack independence to do their jobs, officials say.

The clash between internationalists urging the traditional US leadership role in the world and advocates of an "America First" approach has worn down foreign policy and intelligence professionals in the government, according to the officials.

Secretary of State Rex Tillerson has told friends he will be lucky to last a year in his job, according to a friend, while two officials said national security adviser H.R. McMaster was frustrated by what he sees as disorganisation and indiscipline on key policy issues in the White House.

A source familiar with the situation told Reuters that Mr Tillerson was "very upset at not having autonomy, independence and control over his own department and the ability to do the job the way the job ... is traditionally done".

The source said he had heard nothing about any possible departure, but added: "The situation doesn't seem to be getting any better and, in some respects, appears to be getting worse."

Mr R.C. Hammond, Mr Tillerson's spokesman, denied Mr Tillerson was considering leaving or that his frustrations were boiling over, saying he had "plenty of reasons to stay on the job, and all of them are important to America".

"There's a desperate need for American leadership in the world and that's where the secretary's focusing his attention," he said.

Mr Tillerson scored a policy win last week when the administration certified, albeit reluctantly, that Iran was complying with the 2015 nuclear deal under which Teheran agreed to restrain its atomic programme in exchange for sanctions relief.

He was upset, however, by fierce internal criticism from Mr Trump, as well as his chief strategist Steve Bannon and White House aide Sebastian Gorka, over the decision, said another US official who spoke on condition of anonymity.

"The secretary does not feel that White House staff members should be in a position to conduct hostile cross-(examinations) of Cabinet officials," the official said.

Mr Hammond disputed the account of harsh discord between Mr Trump and Mr Tillerson regarding re-certifying the Iran nuclear deal, saying: "I don't buy this whole thing that there are tensions. Developing public policy is about vetting out ideas," he said.

Following last month's move by Saudi Arabia, the United Arab Emirates, Bahrain and Egypt to boycott Qatar, which they accuse of financing extremist groups and supporting terrorism, Mr Tillerson publicly asked the nations to ease their blockade, and put the onus on both sides to end the crisis.

Less than 90 minutes later, Mr Trump accused Qatar of being a "high level" sponsor of terrorism and suggested he had helped plan the Qatar action with Arab leaders.

"As a government, we offered some confusing signals, but we've since been able to clear up and clarify that," Mr Hammond said.

Politico reported last month that Mr Tillerson was furious with Mr Johnny DeStefano, head of the presidential personnel office, for torpedoing proposed nominees to key State Department posts.

Senior national security officials said McMaster was dismayed that his recommendations, backed by his senior director for Russia, Fiona Hill, about taking a tough stance with Russian President Vladimir Putin, had been ignored.

Mr Trump has questioned the US intelligence community's conclusion that Russia interfered in the 2016 US presidential election to try to help him defeat Democrat Hillary Clinton.

McMaster, a three-star Army general who once praised Trump as a "disruptive" figure, is also troubled by a protracted debate about sending more U.S. forces to help Afghanistan reverse gains by the Taliban, officials familiar with the matter told Reuters.

Asked to respond to the characterisations of the views of McMaster and other officials, a White House official said:"Assertions not of fact but of state of mind in internal thought have no place in a story like this."

While circumspect, Tillerson talked about the challenges of his new job earlier this month, telling reporters that it differed from his former role as chief executive of Exxon Mobil Corp, where "I was the ultimate decision-maker. That always makes life easier." "I knew what to expect and we had very long-standing disciplined processes and decision-making," he said.

"Those are not the characteristics of the United States government."