Is it permissible for a Muslim man to kiss a non-mahram Muslim woman on her cheek (a friendly kiss) and embrace her as a friend, and does the ruling on the sin differ if the doer is in need of a friend's companionship and finds no one else?

It is forbidden for men to take female friends. This behavior is foolishness that incites lust and leads to adultery. Therefore, Allah has forbidden looking at women and commanded lowering the gaze. He has also forbidden mixing with women, being alone with them, shaking their hands, and kissing them. Whoever has fallen into these matters must offer sincere repentance. "And whoever fears Allah — He will make for him a way out" and ease his affairs.