MOSCOW — Russia launched ten drones at Ukraine overnight, all of which were shot down by Ukraine's air defense units, the Ukrainian air force confirmed on Tuesday.

The attack came after Germany threatened Russia with new, tougher sanctions should it not agree to a ceasefire by midnight last night.

"The clock is ticking — we still have 12 hours until the end of this day," government spokesperson Stefan Kornelius on Monday, confirming that Berlin had been coordinating with European partners on additional sanctions.

The ultimatum was given after Russia refused to commit to an unconditional 30-day ceasefire, a proposal initially put on the table by the US in March.

The Kremlin reiterated it would take part in potential peace talks later this week without preconditions, but has yet to respond to Ukrainian President Volodymyr Zelensky's invitation to meet his Russian counterpart Vladimir Putin for face-to-face peace talks in Turkey on Thursday.

"Russian shelling and assaults continue," Zelenskyy wrote on X on Monday. "Moscow has remained silent all day regarding the proposal for a direct meeting. A very strange silence."

The Ukrainian leader had said he fully supported US President Donald Trump's proposal for a "full and unconditional ceasefire," and supported the prospect of Trump personally attending a potential face-to-face encounter with Putin.

Trump said he felt optimistic about the Istanbul talks, and that he was considering flying over to the talks from a visit to Qatar and the United Arab Emirates scheduled for the same day. — Euronews