British Foreign Secretary Liz Truss has accused Russia of running a disinformation campaign against Ukraine.
This should destabilize the country and justify an invasion, said the minister.
"Russia must stop its aggression, de-escalate and open up to serious talks," she tweeted on Saturday.
Russia had previously dismissed allegations by the United States that suspected Russian agents were planning a special operation in eastern Ukraine as "unfounded".
The American government – like Truss now – has accused Russia of creating a pretext for a possible invasion of Ukraine.
As is so often the case, supposed sensational news was being spread by the US without any basis for it, the Russian embassy in Washington said on Saturday.
"As usual, no evidence is presented."
"We have information that suggests Russia has already deployed a group of agents to conduct a false flag operation in eastern Ukraine," White House spokeswoman Jen Psaki said on Friday.
The information indicated that they would also begin to "manufacture provocations" in the media to justify Russian intervention and sow divisions in Ukraine.
Russian Embassy: End "information pressure".
According to US information, the Ukrainian-flagged agents set in motion by Russia could take action against pro-Russian separatists in eastern Ukraine, giving Moscow a reason to invade the conflict region of Donbass.
Russia has repeatedly warned of an attack by the Ukrainian side on the forces loyal to Moscow in the area.
The Russian embassy called on the US side to end the "information pressure" and move on to factual work.
“Russia is against war.
We are for a diplomatic solution to all international problems.” “All of these statements have so far been unfounded and have not been confirmed by anything,” Kremlin spokesman Dmitry Peskov told the state news agency TASS on Friday evening.
Tensions in the Ukraine conflict had increased sharply recently.
The West criticizes a Russian troop deployment near the Ukrainian border and fears a possible attack.
That's why there were talks at different levels this week.
For the first time in two and a half years, the 30 NATO countries and Russia consulted again.
There was also a meeting of the Organization for Security and Co-operation in Europe (OSCE).
At the beginning of the week, representatives of Russia and the USA met in Geneva.
There were no tangible results.
German Foreign Minister Annalena Baerbock (Greens) will travel to Ukraine and Russia on Monday.
The Reuters news agency reported on Saturday that the US government was discussing emergency plans for gas deliveries to Europe with energy companies because of the Ukraine conflict.
Representatives of the Ministry of Foreign Affairs have spoken with the companies about capacities for higher delivery volumes in the event that Russian gas deliveries are interrupted, according to industry and government circles.
National Security Council spokesman confirms contingency planning
A postponement of maintenance work was also discussed in order to keep gas production high.
The companies had explained that a loss of large quantities from Russia would be difficult to replace, referring to the scarce gas supplies around the world.
It was not initially known which companies had been addressed.
The European Union (EU) obtains around a third of its gas requirements from Russia.
American sanctions against Russia could affect deliveries.
A spokesman for the US National Security Council declined to comment on the talks.
However, he confirmed that contingency planning was underway.
An exploration of the effects of possible measures is common practice.
This shows the US determination to take decisive action.