But Zelensky points out no-one has yet made such an offer and whether Nato would consider a move is doubtful.
Russell Martin explains why he was upset with Fabian Hurzeler at the full-time whistle of Southampton's 1-1 draw with Brighton.
Follow live text commentary, score updates and match stats from Deportivo Pasto vs Independiente Santa Fe in the Primera A
Lewis Hamilton has said he is "definitely not fast any more" after another disappointing qualifying performance in his final season at Mercedes.
Harlequins prop Joe Marler says he was no longer able to live up to the mental and physical demands of professional rugby union after retiring from the sport.
Watch Scrum V highlights as Glasgow Warriors edge past Scarlets in the United Rugby Championship.
Experts poring over censuses and newspaper archives have built up a rich picture of their lives.
Brighton's Head Coach Fabian Hurzeler says his side struggled against Southampton's pressing in their 1-1 draw at the AMEX stadium.
Judges are considering how a woman is defined in equalities law - what could their ruling mean?
