Spurs' 1-1 draw against the Foxes means they have now gone five games without a victory since they blew away Manchester City at the start of the month.
Vincent Janssen scored his first Premier League goal from the penalty spot at White Hart Lane but Mauricio Pochettino's men have found goals hard to come by, with Harry Kane still recovering from an ankle injury.
Tottenham have not scored from open play now in 360 minutes and they paid the price again as Leicester's Ahmed Musa grabbed the visitors a hard-earned point.
"It's very frustrating," Dier said
"We controlled the game from start to finish and we know what Leicester are going to do.
"We know their style, so we're very disappointed because we didn't create more chances and obviously didn't score enough goals.
"We'll keep playing, keep improving the way we play, try to get better and try to start winning games because we're drawing too many."
Janssen's goal was his third since joining Tottenham in the summer but he is yet to score from open play in 15 appearances for his new club.
Pochettino rates Kane's chances of returning against Bayer Leverkusen in the Champions League on Wednesday at 50-50 but any contribution is likely to come off the bench, with Janssen expected to lead the line once again
Spurs midfielder Dele Alli praised the Dutchman's impact on the team.
"He loves a penalty," Alli said
"As soon as it was given I knew he was going to run after the ball and everyone was confident he was going to put it away.
"He's a great player, it was only a matter of time before he got his first goal in the Premier League and now hopefully he can get some more."
For Leicester, the draw gave them their first point away from home in the league this season and pushed them up to 11th in the table.
Marc Albrighton, who made his 150th Premier League appearance against Spurs, believes his side fully deserved a share of the spoils.
"We had a game plan to press them high up the pitch and stop them playing out and it worked tremendously well," Albrighton said.
"The lads put them on the back foot and ultimately they didn't like that and we managed to get a very good point.
"We know we always have that goal threat, we got one goal and could arguably have gone on and won it."
Source : PA
Source: PA