Ukraine's NATO membership 'key question' in US-Russia talks: Kremlin

The prospect of Ukraine joining NATO was a "key question" in US-Russia talks in Moscow, the Kremlin said on Wednesday after negotiations with US envoys brought no sign of a breakthrough.

Membership in the alliance is one of the stumbling blocks in US-led efforts to end the four-year war a conflict that US President Donald Trump had pledged to settle within a day of returning to office.