US President Trump has announced an “energy ceasefire” between Russia and Ukraine, in a move that appears to have caught Ukrainian President Zelenskyy off guard.

Trump said in a social media post that the energy ceasefire would take effect immediately, but did not elaborate further. Zelenskyy said Trump’s post was shocking, but later added he was willing to support it if Russia also agreed to halt energy strikes.

But Zelenskyy also said Russian forces were maintaining their attacks on Ukrainian energy targets regardless of Trump’s announcement. Any deal to end long-range drone strikes by Ukraine on targets inside Russia would have to be “reciprocal”, according to Zelenskyy, and it should be backed by “real guarantees” – meaning punitive measures against Moscow from Ukraine’s allies, including the US.

There was no sign that the Kremlin was observing Trump’s ceasefire. According to Zelenskyy, Russian drones took to the sky “throughout the day” on Sunday. There were also several airstrikes, including on energy infrastructure.

Jordan Yap, 30, last made contact with friends and family on 14 September ahead of a planned 10-day solo trek along Peru’s Huayhuash mountain range, 400km north-east of Lima.

In a social media post on Saturday, his friends and family said “with a heavy heart we are sorry to tell you Jordan has been found, and he did not survive”.

The Melbourne man was last seen near the beginning of his trek across the Cordillera Huayhuash circuit, which is regarded as a challenging, high-altitude trek through the remote Andes mountains. His friends and family became concerned after he failed to make contact on his estimated return date, failed to check back into the Krusty hostel in Huaraz and missed a scheduled flight from Lima to Cusco. He also misplaced a satellite beacon he was travelling with days before he set off on the 120km hike, raising further concerns.

A spokesperson from the Department of Foreign Affairs and Trade confirmed it was providing consular assistance to the family of an Australian who had died in Peru.

A surprise suspected accomplice has been arrested in connection with a mass school shooting in Canada that was made notorious after an 18-year-old allegedly killed six children after discussing it with the AI chatbot ChatGPT.

The US Department of Justice said on Tuesday it had detained James Codey Bryant, 30, a resident of western Washington state, on a charge of conspiracy to murder persons in a foreign country. Bryant offered money and “technical advice” to the suspected shooter for six months leading up to the killings, the justice department alleged. Canadian police have identified the suspect in this year’s massacre of eight people – including her mother and half-brother, as well as the six children, making it the second-deadliest school shooting in the country’s history – as Jesse Van Rootselaar, who has a history of mental health problems.

It had been known that Van Rootselaar had used ChatGPT to plan the attack, which took place in February. The safety team at OpenAI, the company that owns the chatbot, flagged Van Rootselaar internally after she conducted conversations with it about gun violence, but the company did not alert police.

OpenAI did reportedly close Van Rootselaar’s account, but she started a second one that was not closed. Victims’ families and the province of British Columbia have sued OpenAI and its CEO, Sam Altman, for failing to report her behaviour.