WASHINGTON: US President Donald Trump (right) shakes hands with newly sworn-in White House Chief of Staff John Kelly at the White House yesterday. - AFP

WASHINGTON: John Kelly was sworn in yesterday as the new White House chief of staff, as US President Donald Trump looked to the retired Marine general for leadership after a shake-up of his top staff. Kelly, 67, is replacing Reince Priebus, who was forced out last week after the spectacular failure of Trump's bid to repeal Obamacare and as an ugly in-house feud spilled into the open.

"We just swore in General Kelly - he will do a spectacular job, I have no doubt, as chief of staff," Trump said after the Oval Office ceremony. "What he has done in terms of homeland security is record-shattering, if you look at the border, if you look at the tremendous results we've had," Trump said.

Trump accentuated the positive in an early morning tweet: "Highest Stock Market EVER, best economic numbers in years, unemployment lowest in 17 years, wages raising, border secure, S.C.: No WH chaos." Republicans are hoping Kelly, who served as Homeland Security secretary for the first six months of Trump's presidency, will succeed in imposing discipline on a White House whipsawed by controversy.

The chief of staff traditionally manages the president's schedule and is the highest ranking White House employee, deciding who has access to the US leader. But many question whether anyone can rein in the mercurial, Twitter-happy Trump, who has appeared to encourage the infighting among various factions vying for influence in his administration. Under pressure from a widening probe into his campaign's contacts with Russia last year, Trump last week attacked his own attorney general for disloyalty, alarming his conservative base, before turning on Priebus.

In another tweet yesterday, Trump hinted that Congress's own health insurance plan should be replaced for its failure to repeal Obamacare, his predecessor's signature reform of the US health care system. "If Obamacare is hurting people & it is, why shouldn't it hurt the insurance companies and why should Congress not be paying what public pays?"

Since taking office six months ago, Trump's tumultuous administration has seen a succession of negative headlines and brewing scandals. Fueling the fire, the billionaire Republican has parted with a number of top officials including his national security advisor, deputy national security advisor and FBI director, among others - an unparalleled turnover for such a young presidency.

Meanwhile, Moscow yesterday sought to justify its decision to purge US diplomatic personnel in the country, as the Kremlin appeared to give up on hopes of improving ties anytime soon under Trump. President Vladimir Putin announced Sunday that Washington will have to cut its diplomatic mission in Russia by 755 employees, as Moscow struck back against new sanctions passed by the US Congress.

The move represents one of the biggest single reductions of US personnel by Moscow, with Putin warning he could retaliate further.  "We have waited long enough, hoping that the situation would perhaps change for the better," the Kremlin strongman said. "But it seems that even if the situation is changing, it's not for any time soon."

Putin's spokesman Dmitry Peskov yesterday insisted that any hopes of mending Russia-US ties rest on "curing the worsening political schizophrenia" in Washington, but admitted the two sides appeared "far away" from any improvement. He did insist Russia remained keen on "continuing cooperation in the areas that correspond to our interests", suggesting Moscow remains open to working together on Syria after agreeing a ceasefire with the US in the south of the war-torn country.

The US State Department earlier called Moscow's move "regrettable and uncalled for" and said it was "assessing the impact of such a limitation and how to respond". US Vice President Mike Pence while on a visit to Estonia yesterday said: "We hope for better days, for better relations with Russia." He stressed that "recent diplomatic action taken by Moscow will not deter the commitment of the United States of America to our security, the security of our allies."

Last Thursday the US Senate overwhelmingly approved a bill to toughen sanctions on Russia for allegedly meddling in the 2016 US presidential election and its intervention in Ukraine. Iran and North Korea are also targeted in the sanctions bill. The White House said Trump intends to sign off on the legislation, despite complaining earlier it would cut off the president's room for diplomatic maneuvering.

Russia's foreign ministry on Friday struck preemptively by ordering Washington to reduce its diplomatic presence to 455 by September 1 to match the size of Russia's missions in the US. It also froze two embassy compounds - a Moscow summer house and a storage facility in the city - from Aug 1. The US embassy has refused to state how many staff it has at its embassy in Moscow and consulates in the cities of Saint Petersburg, Yekaterinburg and Vladivostok.

But Putin confirmed that the move means 755 US diplomats and local Russian personnel will be forced to stop working.  It looks likely that the bulk of those impacted will be Russians. A State Department document from 2013 said that of the 1,279 people then employed by the US mission, 934 were "locally employed" positions. Peskov said it was now a "choice for the US" on which staff Washington chooses to axe from its missions around the country, adding he did not know if this would now make it harder for Russians to get US visas.

"Hopes for improvement in relations between Russia and the US have definitively dissipated," Vedomosti business daily wrote in a front-page editorial yesterday. "The Russian leadership up to the last moment kept hope that it would be possible to somehow build cooperation with the US," Dmitry Suslov from Moscow's Higher School of Economics told Kommersant FM radio. "But in the light of the Congress decision, it is absolutely obvious that this is impossible." - Agencies