As the world waits for Russia's next move over the US-proposed ceasefire deal with Ukraine, only one man has been trusted to head up Donald Trump's envoy to Moscow - and he's far from the typical diplomat.
Initially named as Mr Trump's Middle East envoy shortly after the US election, Steve Witkoff has since been involved in negotiations with Russia about ending the war in Ukraine.
His surprise trip to Moscow last month to achieve the release of US citizen Marc Fogel seemed to secure the 67-year-old as the US leader's geopolitical dealmaker-in-chief.
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Off the back of his first meeting with Russian President Vladimir Putin, Mr Witkoff is believed to be seeing him again later this week to discuss diplomatic proposals - though the Kremlin is yet to confirm this.
He has been chosen to go to Moscow by Mr Trump over US secretary of state Marco Rubio, who on paper is the country's top diplomat, and Keith Kellogg, who was assigned to be the US envoy for Russia-Ukraine peace talks back in January.
So who is Steve Witkoff, and how important a figure will he be as the US tries to navigate peace between Russia and Ukraine?
From New York real estate to the Oval Office
Born in the Bronx, New York State, Mr Witkoff trained as a lawyer in real estate before turning his hand to property development.
In the 1990s he created his company, the Witkoff Group, which owns a number of properties in New York, most notably the Park Lane Hotel and The Woolworth Building.
Similarly to Mr Trump, he brought his close family members into his company, including his wife, Lauren Rappoport, and their sons Zach and Alexander, who is co-chief executive.
As of 2019, the Witkoff Group owned almost 50 properties across the US and the rest of the world.
'My dear friend President Trump'
The billionaire has known Mr Trump for decades, having first met him through a New York real estate company where the now president was a client.
Having remained close, the pair bonded over their mutual love of golf, and weredescribed by US senator Lindsey Graham as "longtime golf buddies".
Mr Witkoff was one of those on the fifth hole with the president at his course in West Palm Beach, Florida, in September last year, when a second apparent assassination attempt was made on his life.
But despite being regular opponents on the course, Mr Witkoff and Mr Trump are very much aligned in politics, with the businessman having donated to the Republican Party during the 2024 election.
He even spoke at the Republican National Convention back in July last year, where he said he had the "privilege" of calling Mr Trump a "true and dear friend for many years, in good times and bad times".
Mr Witkoff also firmly backed Mr Trump's foreign policy, saying at the inauguration parade: "We are done carrying the financial burden of nations that are unwilling to fund their own progress.
"The days of blank checks are over".
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A critical player in Middle East negotiations
During Mr Trump's first term in office, Mr Witkoff played a more minor role, serving as one of the president's Great American Economic Revival Industry Groups - which aimed to combat the effects of the COVID-19 pandemic.
It was over lunch with Mr Trump after his second election win that Mr Witkoff reportedly broached the idea of working on the Middle East - a region he has extensive business ties with, according to NBC.
"That stunned me because I didn't know he was that interested in the Middle East," Senator Graham told NBC back in January, while discussing Mr Witkoff's appointment.
"And Trump looked at me and said: 'Well, a million people have tried. Let's pick a nice guy who's a smart guy'."
Since the beginning of the year, Mr Witkoff has proven to be a critical player in negotiations between Israel and Hamas - helping to secure January's ceasefire deal which has so far seen the release of some of the remaining Israeli hostages in exchange for Palestinian prisoners.
One person familiar with the negotiations described Mr Witkoff to NBC as someone who is "very much engaged" with "his heart is in the right place".
A Middle Eastern diplomat, who spoke with NBC on condition of anonymity at the time, added that the businessman was a tough negotiator but was also able to "empathise" with parents who have lost their children on both sides of the conflict, as he openly spoke about his son Andrew, who died of an OxyContin overdose in 2011 aged 22.
Growing criticism
Despite praise for Mr Witkoff's approach to geopolitics, there is also growing criticism against him.
Shortly after his visit to Gaza back in January, he backed Mr Trump's surprise announcement that the US wanted to "develop" the region and turn it into the "Riviera of the Middle East".
Mr Trump suggested that Gaza's two million people would not return to their territory under the plans, which has been widely criticised as amounting to ethnic cleansing.
Mr Witkoff also faces questions over his first private meeting with President Putin last month, in which he said he had developed a "friendship" with the Russian leader.
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Speaking about his relationship with Mr Putin, he said: "I spent a lot of time with Putin. Talking and developing a friendship and relationship with him…"
He claimed their conversation lasted over three hours.
However, the details of the conversation and what was discussed have never been released, with only translators present at the time.
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