Washington - Russia has cancelled a meeting with senior US diplomats in the wake of Washington's decision to reinforce sanctions imposed over its occupation of Crimea, US officials said on Wednesday.
US Under Secretary of State Tom Shannon had been due in St Petersburg later this week to meet and mend diplomatic fences with Russia's Deputy Foreign Minister Sergei Ryabkov.
Relations between Moscow and Washington are at a low even by the standards of a rivalry that goes back to the Cold War.
Shannon had hoped to address "irritants" in the relationship, like tension over Moscow's intimidation of US diplomats and the US seizure of Russian diplomatic compounds.
But even this minor first step towards finding enough common ground to begin to address more fundamental issues - such as Russia's intervention in Ukraine - has now fallen apart.
"We regret that Russia has decided to turn away from an opportunity to discuss bilateral obstacles that hinder US-Russia relations," said spokesperson Heather Nauert.
The United States on Tuesday added 38 individuals and entities to its sanctions list targeting the Russians and pro-Russian rebels it blames for the fighting in Ukraine.
This appears to have been what triggered Moscow's decision to cancel the meeting, although US President Donald Trump also met Ukraine's President Petro Poroshenko on the same day.
But the State Department insisted that the sanctions were not being expanded, merely "maintained", by adding new targets as Moscow finds ways around the previous embargo.
And Washington insisted the sanctions would stay in place until Russia honours the Minsk agreement to disengage from eastern Ukraine and returns the annexed Crimea region.
"We have regularly updated these sanctions twice a year since they were first imposed," Nauert explained. "Let's remember that these sanctions didn't just come out of nowhere.
"Our targeted sanctions were imposed in response to Russia's ongoing violation of the sovereignty and territorial integrity of its neighbour, Ukraine," she said.