The Magpies boss even admitted that his men could face the drop if he fails to add to his squad before the transfer window closes.
"I think we shouldn't be lost to the fact that we could be relegated," he told reporters.
"Better teams than the one I manage have gone down before. We definitely need a player or two in this window to make sure of our Premier League status. We're under a little bit of pressure."
Injuries and suspensions have forced Pardew to field a weakened side for recent games, but the 51-year-old conceded that his team is still vulnerable at full strength.
"I don't think we have one of the weakest squads, but our squad is too weak," he added. "I'm being realistic.
"I'm not trying to say we're a great team, that we're going to cruise through the second half of the season because in my experience that won't happen. We're going to have to battle down there and it's about time we realised we're going to have to battle."
Newcastle currently lie in 16th place in the Premier League, just two points above the relegation zone with 16 games left to play.