As per reports, updates on the Ukraine-Russia crisis as of Sunday (17 August) are as follows:

• Ukraine has reported advances of up to 2.5 kilometers in the Sumy region, specifically in the North-Slobozhansk direction near the villages of Oleksiivka and Yunakivka, with active operations ongoing along the Russia–Ukraine border.
• European leaders have been invited to join President Trump and Ukrainian President Volodymyr Zelensky at the White House on Monday (18 August) where discussions have reportedly included the possibility of offering Ukraine security guarantees similar to NATO’s Article Five, but outside of the alliance framework.
• Looking ahead, President Trump informed European leaders that he intends to organize a trilateral summit with Zelensky and Putin by 22 August, depending on the outcome of the White House talks scheduled for Monday (18 August).