Putin was shown on state TV greeting Witkoff in St Petersburg's presidential library at the start of the negotiations and state news agencies later said the talks lasted more than four hours.
"The theme of the meeting - aspects of a Ukrainian settlement," the Kremlin said in a statement after the meeting concluded.
Interfax news agency said Witkoff had left the site of the talks - the presidential library in St Petersburg, Russia's second largest city.
Dmitriev called the talks with Witkoff "productive" in a post on X.
However, the talks come at a time when US-Russia dialogue aimed at agreeing a ceasefire ahead of a possible peace deal to end the war in Ukraine appears to have stalled over disagreements around conditions for a full pause in hostilities.
Trump, who has shown signs of losing patience, has spoken of imposing secondary sanctions on countries that buy Russian oil if he feels the Kremlin is dragging its feet on a Ukrainian deal.
Ukrainian officials have in recent days sent the US a list of targets it believes Russia has struck in violation of the energy infrastructure ceasefire the two countries agreed to last month, according to two people familiar with the list.
Following Witkoff's arrival in St Petersburg, Trump posted on social media that "Russia has to get moving".
"Too many people (are) DYING, thousands a week, in a terrible and senseless war," he said.
Putin has said he is ready in principle to agree to a full ceasefire while emphasising that crucial implementation details remain unresolved and what he describes as the war's root causes have yet to be addressed.
Specifically, he has said that Ukraine should not join the NATO military alliance, that the size of its army needs to be limited and that Russia should get the entirety of the territory of the four Ukrainian regions it claims as its own despite not fully controlling them.
With Russia controlling just under 20 per cent of Ukraine and Russian forces continuing to advance on the battlefield, the Kremlin believes Russia is in a strong position when it comes to negotiations and that Ukraine should make concessions.
Ukraine says Russia's terms would amount to a capitulation.
Kremlin spokesman Dmitry Peskov said Putin and Witkoff might discuss the possibility of the Russian leader meeting Trump face-to-face.
Putin and Trump have spoken by phone but have yet to meet in person since the US leader returned to the White House in January for a second four-year term.
with DPA
