President Donald Trump has declared that US relations with Russia "may be at an all-time low".
His top diplomat offered a similarly grim assessment after meeting Russian President Vladimir Putin in Moscow earlier on Wednesday.
"Right now we're not getting along with Russia at all," Trump said flatly during a White House news conference.
Only weeks ago, it appeared that Trump, who praised Putin throughout the US election campaign, was poised for a potentially historic rapprochement with Russia.
But such a scenario seems highly unlikely as the two sides have clashed repeatedly over Syria following last week's suspected chemical attack and US missile strikes.
"It'd be a fantastic thing if we got along with Putin and if we got along with Russia," Trump said.
"That could happen, and it may not happen," he said. "It may be just the opposite."
Earlier in the day, US Secretary of State Rex Tillerson said relations are at a low point and marked by serious distrust.
"There is a low level of trust between our two countries," Tillerson said in Moscow during a news conference with Sergey Lavrov, Russia's foreign minister, adding that the "degradation" of US-Russian ties needs to end.
"The world's two foremost nuclear powers cannot have this kind of relationship," he said.
US and Russia have recently traded caustic accusations following a US strike on a Syrian airbase in retaliation to the suspected chemical attack on a rebel-held town in Syria, blamed by Washington on Syrian President Bashar al-Assad, who is backed by Russia.
Tillerson's comments echoed televised remarks by Putin, who earlier on Wednesday said the trust between the two countries had "deteriorated" since Trump was elected US president.
"One could say that the level of trust on a working level, especially on the military level, has not improved but has rather deteriorated," Putin said in an interview broadcast on Russian television.
"On Syria, they are miles apart and it doesn't seem that there's been any breakthrough at all," Al Jazeera’s James Bays, reporting from the White House, said.
Differences over Assad
Speaking to reporters, Tillerson reiterated Washington's position that Assad must eventually relinquish power - a position starkly at odds with Russia, which has been bombing rebel-held areas in Syria in support of Assad's forces since September 2015.
For his part, Lavrov warned against an international effort to remove Assad from power, citing the cases of Iraq and Libya to argue that the toppling of autocratic rulers by external forces leads to chaos.
He said Moscow was ready to resume a deal with Washington to avoid incidents in Syrian airspace as the two countries lead separate bombing campaigns.
"Today the president confirmed our readiness to return to its implementation on the understanding that the original aims of the air forces of the American coalition are reaffirmed, namely the fight with IS [ISIL] and al-Nusra," Lavrov said.
The deal was suspended after US missile strikes against the Shayrat airbase following a suspected gas attack in Khan Sheikhoun, in an act Moscow labelled "aggression against a sovereign state".
Tillerson said the US is confident in its assessment that Syrian government forces used chemical weapons in the bombing on Khan Sheikhoun and alleged that Syria has used such weapons more than 50 times in the past.
Lavrov said Russia has no intention to "shield anyone", adding that a United Nations chemical weapons watchdog must conduct an "objective and unbiased probe" into the attack that killed dozens of people.
Al Jazeera's Rory Challands, reporting from Moscow, said the press conference highlighted the two diplomats' "differences in style, in position and in views of the world".
"There was no dramatic proposals made, no big deals discussed," Challands said.
"The conversation was basically about how to stop it [the relation] from getting worse, not necessarily about grand steps to make it any better."
The press conference came just moments before Russia again cast a veto at the UN Security Council, blocking a bid from the US, UK and France to condemn the suspected gas attack and push the Syrian government to cooperate with investigators.
China, which has vetoed six resolutions on Syria since the civil war began six years ago, abstained from Wednesday's vote, along with Ethiopia and Kazakhstan.
Ten countries voted in favour of the text, while Bolivia joined Russia in voting no.
Source: Al Jazeera and news agencies