The United States committed at least three gaffes at last week's Group of 20 summit in Hamburg, including mistakenly describing Chinese President Xi Jinping as the leader of Taiwan in a statement.

The US later apologised for referring to Mr Xi as president of the Republic of China - as Taiwan is formally known - instead of president of the People's Republic of China. The other bloopers were an Instagram post by President Donald Trump that called Singapore Prime Minister Lee Hsien Loong the president of Indonesia, and a statement describing Japan's Mr Shinzo Abe as president and not prime minister.

Several analysts say the errors reflect how the six-month-old Trump administration remains understaffed and inexperienced.

Its slashing of costs in the federal government - thought to be part of an agenda Mr Trump's chief strategist Steve Bannon has called the "deconstruction of the administrative state" - cuts across departments but is being felt particularly in the critical arena of international diplomacy.

In a commentary in Politico on June 29, Mr Max Bergmann, who worked in the State Department under the Barack Obama administration, wrote that the department was "being run by a tiny clique of ideologues who know nothing about the department but have insulated themselves from the people who do".

Secretary of State Rex Tillerson and his "isolated and inexperienced cadres are going about reorganising the department based on little more than gut feeling", wrote Mr Bergmann, now a senior fellow at the Centre for American Progress.

Analysts, as well as one former senior American diplomat, told The Straits Times they agreed with Mr Bergmann's observations.

"I have a lot of friends at (the) State (Department) who feel they don't have a future," the former diplomat said on condition of anonymity. "They feel adrift and unhappy."

Asked if this was typical when new management was brought in, the diplomat said: "This is very much beyond what I've ever seen."

The situation could worsen with job cuts on the horizon. Mr Tillerson wants to cut more than 2,300 jobs - around 9 per cent of the workforce.

In addition, many officers are also unsure of policy direction, a survey by the State Department found. Released this month after being commissioned by Mr Tillerson in April, the report found a high level of confusion and demoralisation among career diplomats and civil servants.

Mr Tillerson is reportedly considering merging the State Department and the USAID, the US' external aid agency.

The report quoted one employee - who like others was not named - saying: "Our leaders do not understand our mission and our capabilities."

In all, 55 of the US' ambassadorial posts remain unfilled. In some cases, the failure to fill certain diplomatic positions has left a risky vacuum, analysts said.

Mr Michael Kugelman, senior associate for South Asia at the Woodrow Wilson Centre, told ST that while there were concerns about the State Department, a number of mid-level officers remained focused and motivated.

But he noted: "America's high-level diplomatic absence in Afghanistan is both a security and a credibility risk for Washington."

Mr Trump has yet to nominate an ambassador to Afghanistan, where the US is mired in the longest war in its history, and where it is considering sending more troops to fend off the Taleban, or to Pakistan. Senior State Department positions entrusted with overseeing policy for the region remain vacant - the acting director of the Office of the Special Representative for Afghanistan and Pakistan and her deputy have yet to be replaced after stepping down in May. The office itself is liable to be closed because of downsizing.

Republican Senator Lindsey Graham said after a visit to Afghanistan with other prominent senators over the July 4 US holiday: "All of us realise that it is more than just dropping bombs that will win in Afghanistan."

Chinese Foreign Minister Wang Yi visited Afghanistan and Pakistan last month, talking of a crisis hotline and mediation between Afghanistan and Pakistan, where Taleban fighters get support and refuge.

Mr Uzair Younus, an analyst with the Albright Stonebridge Group, told ST: "China, sensing a vacuum, knowing there can't be a solution without diplomacy, is stepping in."