WASHINGTON - US President Donald Trump had a second, previously undisclosed, private conversation with President Vladimir Putin of Russia this month, the White House acknowledged on Tuesday (July 18), raising new questions about their relationship as the cloud of Russia investigations continues to shadow the Trump administration.
The hour-long conversation in Hamburg, Germany, took place at a private dinner among world leaders at a concert hall on the banks of the Elbe River during the Group of 20 economic summit meeting, with only a Kremlin interpreter present to listen to the exchange.
It followed a formal meeting between the two presidents that lasted more than two hours earlier in the day, and included their foreign ministers for a fraught discussion about Moscow's attempts to interfere in the 2016 US elections.
In the earlier meeting, Trump questioned the Russian president about his role in the US vote. Putin denied his involvement, and the two men agreed to move beyond the dispute in the interest of finding common ground on other matters, including a limited cease-fire in Syria.
But the intimate dinner conversation, of which there is no official US government record, because no American official other than the president was involved, is the latest to raise eyebrows. Foreign leaders who witnessed it later commented privately on the oddity of an American president flaunting such a close rapport with his Russian counterpart.
"Pretty much everyone at the dinner thought this was really weird, that here is the president of the United States, who clearly wants to display that he has a better relationship personally with President Putin than any of us, or simply doesn't care," said Ian Bremmer, president of the Eurasia Group, a New York-based research and consulting firm, who said he heard directly from attendees.
"They were flummoxed, they were confused and they were startled."
The encounter occurred more than midway through the lengthy dinner, when Trump left his seat and approached Putin, who had been seated next to his wife, first lady Melania Trump.
In a statement, a White House official on Tuesday described the meeting as routine and brief, and explained the lack of an American translator by noting that the president was accompanied by a Japanese interpreter who did not speak Russian.
The official, who spoke on condition of anonymity, said that any insinuation that the White House has tried to hide the encounter was false.
A second White House official confirmed that the meeting had occurred but did not offer any details, and insisted on anonymity because the discussion was private.
Russia specialists said such an encounter - even on an informal basis at a social event - raised red flags because of its length, which suggests a substantive exchange, and the fact that there was no American interpreter, note taker or national security or foreign policy aide present.
"We're all going to be wondering what was said, and that's where it's unfortunate that there was no US interpreter, because there is no independent American account of what happened," Stephen Pifer, a former ambassador to Ukraine who also specializes Russia and nuclear arms control.
"If I was in the Kremlin, my recommendation to Putin would be, 'See if you can get this guy alone,' and that's what it sounds like he was able to do," added Pifer, a senior fellow at the Brookings Institution in Washington.
The new revelation comes as the Trump administration struggles to improve its relationship with Russia while under pressure from multiple investigations into possible ties between the American president's campaign and Moscow.
Those inquiries have made what normally would be seen as an attempt at diplomacy between world leaders politically toxic.
The evening after Trump's two meetings with Putin - the first lasting 135 minutes and the later, hour-long dinner conversation - the American president returned to Washington.
On the Air Force One flight back, his top advisers were helping to draft a statement Trump approved about a meeting his son, Donald Trump Jr., attended last year with a Kremlin-connected lawyer who was promising damaging information on Hillary Clinton as part of a Russian government attempt to help the Trump campaign.
"We have the worst relationship as a country right now with Russia than we have in decades, and yet we have these two leaders that, for reasons that do not make sense and have not been explained to anyone's satisfaction, are hellbent on adoring each other," Bremmer said.
"You can take everything that's been given to us, and it doesn't add up."
On Tuesday, the Kremlin intensified its demands that the Trump administration return two compounds in the United States that the Obama administration seized from Russia last fall in retaliation for the election meddling.
After meeting with Thomas A. Shannon, the under secretary of state for political affairs, Sergei Ryabkov, Russia's deputy foreign minister, said he had warned the Americans that there must be an "unconditional return" of the property or Moscow would retaliate.
The State Department said no such agreement was in the offing.
"These deals, so to speak, are going to take some time," Heather Nauert, the State Department spokeswoman, told reporters on Tuesday. "Nothing is coming together anytime soon."
Trump announced Tuesday night that he planned to nominate Jon M. Huntsman Jr., a former envoy to China and Singapore, as his ambassador to Russia.
Huntsman's nomination has been expected for months, but the multiple investigations into Trump's campaign, and whether it colluded with Russia, are likely to figure prominently in his confirmation hearing.