Group 1 - The proposal for a "Putin-Trump" tunnel to connect Russia and the U.S. through the Bering Strait was made by Kirill Dmitriev, a special representative for foreign investment and economic cooperation in Russia [1] - Dmitriev suggested that the construction could be undertaken by Elon Musk's Boring Company, estimating that the cost could be reduced to below $8 billion from the traditional cost of over $65 billion [1] - The Bering Strait is approximately 82 kilometers wide at its narrowest point, with the closest distance between Russian and U.S. islands being about 4 kilometers [1] Group 2 - During a meeting with Ukrainian President Zelensky, U.S. President Trump expressed interest in the tunnel proposal, but Zelensky responded with dissatisfaction [2] - Trump's administration has shown fluctuating attitudes towards the Russia-Ukraine negotiations, shifting from a promise to end the conflict quickly to withdrawing from mediation efforts [2] - Trump has previously pressured Ukraine to make territorial concessions to resolve the conflict, while also stating that no one knows if Ukraine needs to trade territory for peace [2]