Pakistan succumbed to a 76-run defeat against the defending champions in their first Pool B game in Adelaide on Sunday.
“We can all see what went wrong,” Waqar told reporters. “We didn't play well, India played better than us by building partnerships, probably we took more pressure.
“But we have to realise that it's just the start and there are more games to play and we will come back in the matches ahead.”
Pakistan will look to put things right in their second game in Christchurch on Saturday against the West Indies, who also suffered a shock defeat at the hands of Ireland.
Waqar repeated his team were not amongst the title favourites, a statement which he gave before the departure for New Zealand last month. Then, such pessimism was greeted with severe criticism from former Pakistan players.
“I think it's the same, I back that again, I am not saying that we have become favourites. Of course, saying that releases pressure from players when you are not favourites.
Waqar, who is in his second stint as coach after guiding the team to a semi-final finish in the 2011 World Cup, blamed poor batting for the India loss.
“Unfortunately our batting did not click,” said Waqar, of Pakistan's batting which failed to chase a target of 301, wrapped up for 224.
“A target of 300 runs in Australia and New Zealand is chaseable, this has become the norm, a par total, and we have to chase down 300 in games ahead,” said Waqar.
Pakistan desperately need a win against the West Indies to keep up their chances of a quarter-final place.
“We know the importance of the game so we will try to have a positive frame of mind and do well,” said Waqar, who admitted that experimenting with Younis Khan as an opener had failed.
“The experiment to use Younis wasn't successful,” said Waqar. “It's not too tough to drop a senior player but in a tournament like the World Cup you try to use maximum experience.
“When we used Younis at number three or four he was not scoring runs so as per the requirement we used him as an opener but it didn't work.”
Younis, playing his fourth World Cup, has managed just 73 runs in seven matches with a highest of 25 since the team's arrival in New Zealand last month.
Pakistan have opener Nasir Jamshed waiting in the wings and he is likely to replace Younis, who made just six on Saturday, if the veteran is dropped.