President Donald Trump has sought to advance prospects for co-operation between Russia and the US in Syria and elsewhere in a rare Oval Office meeting with Vladimir Putin's top diplomat.
Foreign minister Sergey Lavrov's talks with Mr Trump were already destined to be a closely watched affair, given the dire state of US-Russian relations and diplomatic wrangling going on over a Moscow-backed deal to stabilise Syria.
Mr Trump's decision on the eve of the meeting to fire the FBI director overseeing a Russia-related investigation injected further intrigue into Mr Lavrov's first visit to Washington since 2013.
Mr Trump "raised the possibility of broader cooperation on resolving conflicts in the Middle East and elsewhere", according to a White House statement.
Mr Trump and Mr Lavrov met in private, though both sides cast the session as a sign of ties having improved since the US leader's assessment of them last month as being at an "all-time low".
On Wednesday, they focused on areas of budding agreement and Mr Lavrov sought to blame the recent acrimony on former president Barack Obama.
"The previous administration bent over backwards to undermine the solid foundation of our relations," Mr Lavrov told reporters at the Russian embassy after meeting Mr Trump.
"We have to start at a very low level."
In contrast, he credited Mr Trump and secretary of state Rex Tillerson, whom he met earlier in the day, with taking a "businesslike" approach that is "free from ideology", focused on reaching agreements.
None were apparently reached on Wednesday.
The meeting was Mr Trump's highest level face-to-face contact with a Russian official since taking office and in itself represented modest progress.
The last time Mr Lavrov visited the American capital was before Russia annexed Crimea from Ukraine and intervened militarily in Syria to help President Bashar Assad - actions that fuelled US-Russian tensions.
The Russian diplomat steadfastly refused to weigh in on Mr Trump's decision to fire James Comey, the former FBI director, who had been overseeing investigations of alleged Russian interference in the US election and possible collusion by Mr Trump's campaign.
Mr Lavrov called it a US decision, echoing Mr Putin, who said Russia had nothing to do with Mr Comey's dismissal.
"Was he fired? You're kidding," Mr Lavrov said sarcastically, feigning surprise as he started his day of meetings in Washington.
Mr Comey's dismissal escalated concerns in both parties that Mr Trump may be trying to undermine an investigation that appears to be gaining steam.
Mr Trump insisted that was not the case. He said on Wednesday he fired Mr Comey because he "was not doing a good job".
Still, the overlap between the investigation and Mr Trump's diplomatic efforts made for uncomfortable optics.
Russia's foreign ministry tweeted a photo of Mr Trump shaking hands with Mr Lavrov and the Russian embassy posted another of the president greeting another participant in the meeting - ambassador Sergey Kislyak, a central character in various Russia-related investigations because of his contacts with several individuals close to Mr Trump.
Mr Lavrov chalked up the controversy to "noise" and to "false news" - invoking Mr Trump's frequent references to the Russia allegations as "fake news".
On Syria, where Russia has backed Assad's forces and the US has supported anti-Assad rebels, the talks appeared to indicate a slight narrowing of differences.
Russia, Turkey and Iran last week agreed on a plan for four "de-escalation zones" in the Arab country to quell a civil war that has killed some 400,000 people and contributed to global refugee and terror crises since erupting in 2011.
The US is not party to the deal and has reacted cautiously, especially given its misgivings about Iran's role.
But Mr Lavrov said he detected a US willingness to participate, especially with a zone being formed in Syria's south, near the border with Israel and Jordan.
"We believe the US is really interested in that," Mr Lavrov said, acknowledging that details of the plan still needed to be worked out.
The zones would not cover areas where the US-led coalition is fighting Islamic State, but enforcement and other questions remain unanswered.
In his earlier meeting with Mr Lavrov, Mr Tillerson emphasised the US would not lift sanctions on Russia related to Ukraine until Moscow reverses the actions that triggered the punishment - namely, its Crimea annexation.
Moscow wants the elimination of those and election-related sanctions imposed by Mr Obama.
Nevertheless, Mr Lavrov struck a conciliatory tone and said Russia is not intending to retaliate.
"Putin doesn't want to follow the lead of those who are trying to poison our relations to the point of no return," he told reporters.