Ghana coach Kwesi Appiah says the Black Stars will be at their maximum firepower when they face little-fancied Guinea Bissau in their decisive 2019 Africa Cup of Nations clash on Tuesday.

The Black Stars must win the match to secure automatic qualification into the knock-out phase of the tournament in Egypt and any result less than that could prove catastrophic for the four-time champions.

With just two points after two matches in the tournament, the Black Stars must win the game against the West African side to avoid a disgraceful first round exit.

Ghana remain winless at the tournament after they were held to a 0-0 draw by Group F leaders Cameroon at the Ismailia Stadium on Saturday.

Kwesi Appiah's side could only manage a 2-2 draw against Benin in their opening game and they were frustrated again versus a Cameroon side who move on to four points at the group's summit.

“I have always said that you need to give every team that you are playing 100 per cent respect," the former international defender Kwesi Appiah said.

"Guinea Bissau is a strong team and as you saw they played against Benin, it was 0-0, and this shows that the mere fact that they have qualified for the competition, that means they are a good side.

“There is no way we are going to underrate them. We are going out there to give them a very good game.”

Ghana are under pressure when they face Guinea-Bissau on Tuesday in their final group game.

Cameroon, meanwhile, are in pole position to qualify for the last 16 and face Benin on the same day.

With Benin tied on points with Ghana, the Black Stars must win the match against Guinea Bissau to qualify.