France's new foreign minister Catherine Colonna said on a visit to Kyiv Monday that Paris is ready to boost military aid to Ukraine to help it counter Russia's invasion.

"France is not at war with Russia", but it will "continue to reinforce arms deliveries," Colonna said at a news conference with her Ukrainian counterpart Dmytro Kuleba.

She said the arms will arrive "in the coming weeks."

Colonna defended French President Emmanuel Macron, who has come under fire in Ukraine and some Western countries for holding frequent phone calls with Kremlin chief Vladimir Putin.

"The conversations between the President of the Republic and Vladimir Putin are direct and frank," she said. 

She added that "it does not seem to be the hour for negotiations but, as President Zelensky said, the day for dialogue will have to come.

"We are at Ukraine's side to facilitate this if it wishes," she said.

The pair also discussed Ukraine's closer integration with the European Union and Colonna said France was "in favour of a rapprochement with Ukraine and even an accelerated one. It is a legitimate request," she said. 

Kyiv has expressed frustration at some EU countries for not wanting to fast-forward its member status in the face of Moscow's attack.

"I asked my French colleague not only to support the decision to grant Ukraine EU candidate status, but also to convince those who still doubt the expediency of this step," Ukraine's Kuleba said.

Colonna, who took office this month, also visited the town of Bucha, where Russian forces allegedly killed hundreds of civilians. 

"This should never have happened. It must never happen again," Colonna told reporters after visiting an Orthodox church in Bucha.

She said France stood with victims of alleged Russian atrocities and that her country would "do everything in its power to restore peace".

Colonna said France had been "the first one to respond" by dispatching gendarmes to Bucha to probe killings alongside Ukrainian investigators.

She said she hoped that work would be completed as quickly as possible, "so that families can see their loved ones laid to rest in proper graves".

Colonna is the highest-ranking French official to visit Ukraine since the beginning of the Russian invasion on February 24. 

She was also to hold talks with President Volodymyr Zelensky to discuss Moscow's blockade of Ukraine's ports and the impact on global food security.