At least seven people have been killed including two children during intense Russian drone and missile strikes on Ukraine, officials say.

A kindergarten was hit in Ukraine's second biggest city Kharkiv and there was widespread damage in Kyiv. Children were among the 27 people wounded.

Hours earlier, US President Donald Trump said his plans for an imminent summit in Budapest with Russia's Vladimir Putin had been shelved as he did not want a wasted meeting.

President Volodymyr Zelensky said the attacks proved Moscow had not come under enough pressure for its continued war.

The Kremlin has rejected calls for a ceasefire along the current front lines made both by Trump and European leaders. However, Russian officials said preparation for a Trump-Putin summit was continuing, disputing the US president's assessment that it had been put on hold.

Kremlin spokesman Dmitry Peskov said a date had yet to be agreed upon and careful preparation was needed. He said a summit was the mutual desire of both presidents and most of the gossip and rumours surrounding it were untrue.

Zelensky's European trip comes days after discussions in Washington, where he sought support for long-range Tomahawk missiles. He expressed that the Kremlin's reaction to the summit being delayed was directly linked to the lack of military support for Ukraine.

As the bombings continue, Kharkiv officials reported casualties, underscoring the horrific toll of this ongoing conflict on civilians, particularly children in vulnerable communities.