Celtic chief Gordon Strachan is believed to be willing to loan out Kennedy.
"It seems a simple enough thing to get done but we seem to be finding it difficult between the two executives," McGhee told the Daily Record.
"We can't, apparently, afford the full amount, so we're haggling to see if we can make it any less.
"But if either or both of those things happen - we give a bit and they give a little - he can come here.
"John wants to come here and has made that absolutely clear but at the moment we have not come to an agreement.
"Regardless of other centre-halves, John is the one I want. It would take a chunk of it (Motherwell's budget) but I feel it is a worthy and worthwhile investment."