Brendan Rodgers' side face a Boxing Day visit to Manchester City before heading to Stamford Bridge to take on Chelsea three days later as they look to remain at the top of the table.
The Reds enter the fixtures as league leaders due to their superior goal difference over Arsenal, and Allen admits that the forthcoming games will prove a stern test of their title-winning credentials.
"To be top near to Christmas is a great achievement. Naturally, we will play it down a little," he told the Daily Star.
"But the next two games are going to be big ones. We will see where we are after we have played them.
"It's a massive challenge but one to look forward to. The run of form we are on and the way we are playing, we are certainly looking to go to City and get a result.
"City have an incredible record at home, as do Chelsea, but records are there to be broken. We have got to be ambitious that we can be the team that goes there and do that."
Allen also praised team-mate Luis Suarez after the striker made it 10 goals in four games during the 3-1 win over Cardiff, saying that his new contract has been a lift for the whole squad.
"Luis is delivering week in, week out," he said.
"That is the sign of a world-class player. He is scoring goals for fun, creating goals and as a team we are killing teams off.
"His new contract was a massive boost for all of us players - not only going into the Cardiff game but also for the rest of the season.
"For him to commit his future here is fantastic news for the club and for the supporters. That is the kind of signal you send out when you want to attract some big players.
"It seemed to be concluded quickly which shows Luis' desire to be at this club. The dressing room is an ambitious one and we have a lot of determined and hungry players who are looking to achieve things.
"With the history of this club there is no reason why we shouldn't be competing at that top end of the table."