Tottenham Hotspur face a conundrum over Toby Alderweireld's future after the latest contract talks with the defender ended in stalemate, a source close to the situation has told ESPN FC.

Spurs have been trying to tie Alderweireld to a new deal for more than a year but are no closer to an agreement after talks broke down last month.

Alderweireld's current deal, worth £50,000-a-week, expires in 2019.

The Belgium international, 28, is aware of his value and would like a long-term contract worth closer to £150,000-per-week -- in line with the best-paid centre-backs in the Premier League -- to see him towards the end of his career at the highest level.

Spurs are reluctant to meet Alderweireld's demands, with Harry Kane currently their best-paid player on around £110,000-a-week plus significant performance-related bonuses.

The club can trigger an option to extend Alderweireld's contract by a year to 2020, but that would activate a buyout clause allowing him to leave if they receive a £25 million bid before the final two weeks of the 2019 summer window.

Alderweireld, who has been among the best defenders in the Premier League since he joined from Atletico Madrid in 2015, is aware that there would be no shortage of interest.

Toby Alderweireld's current deal expires in 2019. Tottenham Hotspur FC/Tottenham Hotspur FC

But Spurs also believe they have a strong hand given that they have had good results without him this season and know that he has suffered serious injuries in the last two campaigns.

Alderweireld described the recent hamstring injury that sidelined him for over three months as the worst of his career.

His return from it has further complicated the situation. He has believed himself fully fit for some time -- and declared himself ready to return on Jan. 24 -- but did not feature until last week's FA Cup win over Newport and was then left out of the squad for the games against Arsenal and Juventus.

Spurs manager Mauricio Pochettino explained his position to Alderweireld during a two-hour meeting after the draw at Liverpool on Feb. 4 and said on Monday: "The player always feels they are fit to play, but it is our responsibility to take the best decision. When you can't play, it's difficult to accept."

Pochettino does not want to take a risk with Alderweireld's long-term fitness and said of his decision not to take him to Juventus: "He is 28 and it was a massive injury that we need to care for, and be cautious because we cannot put his career at risk."

Pochettino is always cautious with players returning from long-term injuries and has taken that approach with both Danny Rose and Erik Lamela.

But his caution could also stem from the fact that it would be harder to sell an injured player in the summer, if it comes to that, although neither Spurs nor Alderweireld have given up hope of reaching an agreement.