McLaren team's racing director Eric Boullier has claimed they want "Fernando Alonso to make a decision" over a move to the British outfit before the Abu Dhabi Grand Prix on 23 November.
Recent reports in Italy claimed the negotiation between the two-time F1 champion and McLaren were almost a done deal, after the Spaniard agreed a two-year contract - with the option of a third - and a salary of £27m a year.
Boullier has confirmed the negotiations with the Ferrari driver to return to the team where he spent the 2007 season.
However, the team's racing director said the deal is still yet to happen and urged Alonso to make a decision before the end of the month.
"We want Alonso's decision between Brazil and Abu Dhabi," Boullier said during an interview with BILD.
"We have held conversations with Alonso, we know he will be a good fit for us and he has told us that he interested in joining."
"We want a long-term partnership, not just for a year."
Meanwhile, Alonso has said he is still considering a future withFerrari.
"The press has been speculating for the last three or four months. Last week they said I was going to Lotus or that I was going to buy Marussia. As always the focus is on the track and the future is the second, third or fourth priority in my head," he said.
"I still have to see what the best option (and maybe) renewing with Ferrari for the long- term, which is something we've been talking about during the year. There are many things I have to think about. Hopefully we can say something soon."