The girlfriend of an American man on the missing Malaysia Airlines flight 370 is writing heart-warming letters to him on Facebook, and is hoping to find him "soon" - even though the agonising search operation across the Southern Indian Ocean has so far found nothing.

Sarah Bajc is the girlfriend of Philip Wood, who was flying with 238 other passengers when flight MH370 went missing over the South China Sea on 8 March.

While waiting painfully for any news from the Malaysian authorities, Bajc has posted several love notes for Wood on her Facebook page.

In one of her several posts on Facebook, Bajc says to her 'Dearest love' Wood: "I'm doing my best to bring you hope and courage to continue the fight. So many people have joined in ... it has become a prayer storm."

She later says "My dearest Philip ... it has been a crazy few days. the positive energy levels are building higher and higher. can you feel it?"

Bajc, a business teacher at an international school in China, had planned to move to Kuala Lumpur to start a new life with the missing IBM executive. Wood was on his way to Beijing to help Bajc move when the plane vanished mid-air.

"The risk of not knowing is what frightens me the most, when you don't know, the wound just keeps getting bigger and bigger. Not only can it not start to heal, but it actually gets worse," Bajc told ABC News.

You can read her heart-warming love letters here.