NEW YORK – McDonald’s wants to bring back that loving feeling.

As the world’s biggest hamburger chain fights to hold on to customers, the company on Friday unveiled a new marketing strategy and ads it says will emphasize the “love” in its long-running “I’m Lovin’ It” slogan.

As part of the push, McDonald’s released TV ads it says will begin airing this week, including an animated video where the Joker and the Batman, a mail carrier and a dog, a blue donkey and red elephant and Smurfs and Gargamel show affection to each other and share McDonald’s products.

The upbeat spot ends with the words “Choose Lovin’,” encompassed by a ring of hearts.

The push to identify itself with love and positivity in the minds of customers comes at a challenging time for McDonald’s, which is facing shifting eating habits, intensifying competition and growing calls by workers and labor organizers for higher pay and a union. Sales for its flagship U.S. division have continued to struggle even after McDonald’s replaced its president twice in less than two years. In November, sales fell 4.6 percent at established U.S. restaurants.

Allen Adamson, chairman of brand consulting firm Landor North America, said McDonald’s is trying to achieve something similar by focusing a massive organization behind a big, simple idea that “sits above the quality of its food.” But he said the challenge for McDonald’s will be in tying “loving” back to the experience of eating at McDonald’s.

“What does loving have to do with how McDonald’s is going to make my experience better?” he said.