Barcelona woke up with a familiar sinking feeling on Wednesday, another Champions League hangover, after Paris Saint-Germain thrashed them 4-1 at home to eliminate them in the quarter-finals.
Mbappe wrapped up the win in the 89th minute.
"We have no choice. We have to go and win there."
Scorer of 39 goals for his club this season, Mbappe was described as "invisible" against Barcelona by newspaper Le Parisien, which pointed out that he managed just three attempts on goal during the game, none of which troubled Barcelona goalkeeper Marc-Andre ter Stegen.
Barcelona coach Xavi Hernandez hailed his side's 3-2 win away to Paris Saint-Germain in the first leg of their Champions League quarter-final on Wednesday, insisting it showed the Catalans could once again compete with the very best teams in Europe.
The French government said there was no "concrete threat" to Paris Saint-Germain's Champions League match against Barcelona on Wednesday in the French capital after Islamic State threatened to attack all four quarterfinals.
“I am ready and, as always, I am not going to hide. Seeing the dynamic we have, I'm sure we're going to give it our all, then the result... It's in God's hands,” Mbappe told Telefoot
Kylian Mbappe had a penalty saved but then scored the only goal of the game as Paris Saint-Germain beat Rennes 1-0 in the last four of the French Cup on Wednesday to set up a final showdown against Lyon.
Paris Saint-Germain coach Luis Enrique said Tuesday he was "very happy" with star attacker Kylian Mbappe during a press conference on the eve of his side's French Cup semi-final clash with Rennes, as he downplayed rumours of a rift.
Mbappe has already told PSG that he intends to leave at the end of the current campaign when his contract expires.
"We have to realise that if we play like this in the matches that lie ahead, we could be in for a big disappointment, and we don't want that to happen to us," Mbappe told reporters on Monday.
Kylian Mbappe believes he will know which club he will join next season before the European Championship kicks off in June, the France forward said on Friday.
Thierry Henry's France side are firm favourites to progress following a kind group draw for men's football at the 2024 Olympic Games on Wednesday, as the hosts wait to see if Kylian Mbappe will be made available.
Vitinha put PSG ahead at the Stade de la Mosson and Mbappe doubled their advantage midway through the first half, only for an Arnaud Nordin header and a Teji Savanier penalty to bring Montpellier back level at the interval.
Mbappe struck his 35th club goal of the season.
Ligue 1 leaders Paris St Germain were held to a 2-2 home draw by Reims on Sunday after PSG boss Luis Enrique benched top scorer Kylian Mbappe, who played only the last 20 minutes.
Kylian Mbappe insisted he had "no problem" with Paris Saint-Germain coach Luis Enrique after scoring a brace in his side's win over Real Sociedad in the last 16 of the Champions League on Tuesday.
Kylian Mbappe lethally fired Paris Saint-Germain into the Champions League quarter-finals with a brace in a 2-1 win at Real Sociedad on Tuesday, his team cruising through 4-1 on aggregate.
PSG have suffered numerous humiliating defeats at this stage of the Champions League in recent years but they are ideally placed to advance to the quarter-finals this time after winning 2-0 at home to the Basque side in last month's first leg.