Novo Nordisk should still be able to introduce its long-acting insulin Tresiba on the U.S. market before rival products, despite being hit by a delay, the CEO of the Danish pharmaceutical company has said.

In February 2013, the U.S. Food and Drug Administration (FDA) unexpectedly refused to approve the drug until Novo Nordisk conducted additional tests over potential heart risks. The Danish company lost about $14 billion in market value after the decision.

"We judge that we still have an opportunity to launch Tresiba in the U.S. if we are successful in the trials, before any significant competitive products are being entered into the market," Lars Rebien Sorensen told the company's annual general meeting.

French drugmaker Sanofi recently sued Eli Lilly, delaying the U.S. firm's introduction of a generic version of Sanofi's Lantus insulin product, a rival to Tresiba.

The suit is seen as positive for Novo Nordisk, the world's largest insulin producer, because it gives the company an opportunity to bring Tresiba to the market before a generic version of Lantus is launched.

Goran Ando, who took over as chairman of the board at Novo Nordisk last year, told the news agency Reuters that getting Tresiba approved by the FDA was one of the most important short-term goals for the group.

"I think perhaps the biggest challenge (in 2014) will be to keep up the growth in the U.S., which has been a growth engine for us, without having our new long acting insulin Tresiba on the market there," he said.