The US has increased intelligence sharing with Ukraine to include information on targets deeper inside Russian territory, after the summit between US President Donald Trump and Russian leader Vladimir Putin in Alaska this summer failed to produce a peace agreement, according to two sources familiar with the matter, CNN reports.

The shift to provide intelligence with a focus on energy-related sites and facilities that the Trump administration had previously told Kyiv were off limits occurred following Trump’s meeting with Putin at a US military base in Alaska this summer, both sources said. 

The Trump administration had asked Ukraine to avoid striking Russia’s oil, gas and energy infrastructure ahead of the summit as officials pursued a peace deal with Moscow. 

But the US gave Ukraine the green light to resume attacks against those targets after both leaders left Alaska without an agreement in hand, one of the sources said.

With US approval, Ukraine has now adopted a deliberate strategy of targeting Russia’s energy-related infrastructure, the source said.

Ukraine believes targeting Russian energy infrastructure is one of the few remaining ways to produce strategic effects, the source added.