KYIV, Ukraine — Three senators visiting on Wednesday pressed Ukrainian President Volodymyr Zelensky to ramp up efforts to combat corruption and reform the country’s Soviet-era security service while he described his hopes for President Joe Biden’s summit with Russian leader Vladimir Putin.

Russia invaded and seized Ukraine’s Crimean peninsula in 2014 but was forced to a stalemate in the eastern region of Donbas, where it continues to provide military assistance to separatists. That hot conflict has not ended despite a peace treaty signed a year later in Minsk. Sens. Jeanne Shaheen, Rob Portman, and Chris Murphy met Wednesday with Zelensky to discuss reforms but recognized Ukraine needs military assistance to survive its struggle with Russia.