London, April 18 : Keira Knightley is having a hard time to find a balance between her personal and professional life.

The actress, who has been involved with her Pride and Prejudice co-star Rupert Friend for more than four years, revealed she was yet to know what was more important, love or career.

"It''s hard to have a relationship when you''re working so much. But then you have to think, ''What is actually important in life? Is career your only thing?'' the Daily Express quoted her as telling the Australian edition of Marie Claire.

"If it is, then it''s easy, but if it isn''t that''s sad, because there''s going to come a day when you''re left lonely. It''s a difficult balance.

"I think you''ve got to strive for balance. It''s the striving that counts. If you''re someone like me, who has always been very driven, to suddenly step back and decide, ''Well, love is the only thing'', then you need to build up your relationships," she added. (ANI)