US Patience Runs Out: Trump-Putin Summit Canceled

The US has canceled the planned summit between Trump and Putin. What led to this decision?
Following a harsh note from the Russian Foreign Ministry, the US canceled the summit planned between Trump and Putin. The cancellation is said to be a result of a tense phone call between the foreign ministers of both countries.
Trump stated that the cancellation of the summit indicates a significant shift in US policy towards Ukraine, especially after Moscow showed no intention to negotiate.
Trump mentioned that he does not want to have a 'wasted meeting' with Putin, but he also indicated that a future meeting is still possible.
The tough demands from Russia and Trump's stance have put diplomatic relations between the two countries in a difficult situation. It is believed that new talks will not be meaningful unless significant steps are taken regarding the war in Ukraine.