The burly Belgian has enjoyed a fantastic opening half of the season with the Toffees, netting nine goals in 19 outings in the blue shirt.
This has led to rumours that the Toffees may look to keep the 20-year-old beyond his temporary spell on Merseyside by tempting Chelsea with a summer offer.
However, Martinez says that the London club are not willing to let Lukaku leave, rendering a deal impossible:
“I know Chelsea are not contemplating listening to any offers and Romelu is highly regarded there,” he is quoted by the Daily Star.
“I rate Romelu as one of the best strikers in European footballnow. We want to keep Romelu as long as we can, but the reality is he’s on loan for the season.
“They need to be the ones that give us the hint if it’s possible or not in the future.
“As you can imagine the situation is we need to wait until the end of the season.”
Everton are also in the market for another striker before the current window closes, with Lacina Traore and Michy Batshuayi having both been linked with the club after Nikica Jelavic left to join Hull in a £7.5m deal:
“We want another striker, but to help Rom not replace him (Lukaku).
“What is important is not spending money for the sake of it, but with a clear, long-term strategy as well.”