Watch: Zelenskyy wants of possible "violent" attack as Kyiv marks 31 years of independence
Ukrainian President Volodymyr Zelenskyy has warned Russia may increase its attacks this week to coincide with Ukraine's Independence Day.
The annual celebration on 24 August also marks exactly six months since Vladimir Putin ordered the invasion on Ukraine.
Zelenskyy has called for vigilance, saying the Kremlin could order something "particularly disgusting, particularly cruel", before Wednesday.
He also said he had discussed "all threats" with French President Emmanuel Macron, who also spoke with Putin last week.
Word was also sent to other leaders including Turkish President Recep Tayyip Erdogan and UN secretary-general Antonio Guterres.
"All of Ukraine's partners have been informed about what the terrorist state can prepare for this week," Zelenskyy said in his nightly video address, referring to Russia.
In a video released on social media he said: "We must be aware that this week Russia may do something particularly disgusting, particularly cruel, such is the enemy of ours.
"But in any other week during these six months Russia has done the same thing constantly, disgusting and cruel.
"One of the key tasks of the enemy is to humiliate us Ukrainians, to devalue our capabilities, our heroes, to spread despair and fear, to spread conflicts.
"Hence it's essential never, for a single moment to give in to this enemy's pressure, not to wind yourself up and show weakness."
Zelenskyy also warned that Russia would be violating international rules if it went ahead with plans to haul captured Ukrainian defenders from Mariupol before the courts, and would stop international dialogue for peace.
"If this despicable show trial were to go ahead ... this would be the line beyond which negotiations are no longer possible," he said. "There will be no more conversations. Our state has said everything."
The Financial Times, in an article published Sunday, quoted Gennady Gatilov, Moscow's ambassador to the United Nations in Geneva, saying Turkey's Erdogan had tried to facilitate dialog.
But he dismissed speculation about talks between Zelenskyy and Putin, saying there "was not any practical platform for having this meeting," the report said.
In Russia, authorities are investigating a suspected car bomb attack outside Moscow that killed the daughter of Alexander Dugin, an ultra-nationalist Russian ideologue who advocates Russia absorbing Ukraine.
While investigators said they were considering "all versions" when it came to establishing who was responsible, the Russian Foreign Ministry speculated there could be a link to Ukraine, something a Zelenskyy adviser dismissed.
"Ukraine, of course, had nothing to do with this because we are not a criminal state, like the Russian Federation, and moreover we are not a terrorist state," Mykhailo Podolyak said on Ukrainian TV.
As Ukraine prepares to mark its Independence Day embroiled in a war that has flattened towns and cities, killed thousands and forced millions to flee, officials have reported more Russian strikes on targets in the east and south of the country.
In the eastern Bakhmut region, Russian forces inflicted damage from artillery and multiple rocket launcher systems in the areas of Soledar, Zaytseve and Bilogorivka settlements, Ukraine's General Staff said in its daily update on Monday.
They continued to focus their efforts on establishing full control over the territories of Luhansk and Donetsk regions, maintaining the captured areas of Kherson and parts of Kharkiv, Zaporizhzhia, and Mykolaiv regions, the General Staff added.
Of particular concern is the shelling of Nikopol.
As a result of overnight rocket attacks on Nikopol, Krivyi Rih and Synelnykovsky districts of the Dnipropetrovsk region, four people were injured, regional Governor Valentyn Reznichenko wrote on Telegram on Monday.
Over the past 24 hours, two civilians were killed in the Donetsk region in Ukraine's east, the regional administration said.
Russia denies targeting civilians.