In the wake of a 2-1 loss to Hull which leaves the Hammers six points off the drop zone with eight games left, the club's hierarchy moved to back their manager.
Amid reports about his future, a statement from the West Ham board said: "To end speculation once and for all, the West Ham United Board feel it necessary to announce that we have 100 per cent faith in Slaven Bilic's ability to lead West Ham United."
"Despite press speculation to the contrary, the manager's position is not under threat. The board know that Slaven and his coaching staff have the full backing of the playing squad and the overwhelming majority of supporters to lead West Ham United out of this difficult spell," the statement continued.
"The board now urge all supporters to unite behind the manager, his staff and the squad as we go into some important games. We all have complete confidence in their ability to end a testing run of results and finish the season on a high."
West Ham have picked up just two points from their last six games and are on a run of four successive defeats. They are next in action on Wednesday when they face Arsenal at the Emirates Stadium.
The backing from above comes as Bilic warned his side they must stop conceding goals from set-pieces if they are to avoid a Premier League relegation fight.
Andy Carroll's 50th Premier League goal gave West Ham a deserved half-time lead at Hull on Saturday, but the home side hit back through Andrew Robertson and Andrea Ranocchia to clinch a 2-1 win.
"You can't say that we were a flat team or whatever," said Bilic. "We were very motivated, we were very up for it.
"But as I said you can't concede like this, especially late in the game and especially from the set-pieces because we've conceded more than a few recently.
"We are working on that. Big time."