MTN Group, Africa’s biggest mobile operator, is sticking to its 2018 dividend target despite new U.S. sanctions making it harder to repatriate cash from its Iran joint venture, the company said on Wednesday.

Chief Executive, Rob Shuter, said on a conference call in Johannesburg that the company stood by its plan to increase payouts by 10 to 20 per cent over the next three to five years to its investors.

“Despite continued challenges in repatriating funds from MTN Irancell, the board remains committed to plans to declare a total dividend of 500 cents per share for 2018,” Shuter said.

MTN, which reported a 7 per cent drop in half-year profits on Wednesday, has around 3.4 billion rand ($256 million) in accumulated dividends and loans from its joint venture in Iran.

Sanctions imposed on Tehran by the United States this week have already led banks and many companies around the world to scale back dealings with Iran.

President Donald Trump said on Tuesday that companies doing business with Iran would be barred from the United States.

He, however, said the sanctions may limit the ability of the group to repatriate cash from MTN Irancell, including future dividends.

The company declared a dividend of 175 cents per share in the first six months of the year, meaning it would have to pay 325 cents to reach in second-half of the year to hit the target.

MTN said headline EPS, the primary measure of profit in South Africa that excludes certain one-off items, fell 7 per cent to 215 cents in the six months through June due to unfavourable currency swings as well as a lower contribution from joint ventures and associates.

Those contributions dropped by a hefty 66 per cent to 197 million rand, mainly due to a drop in the contribution from MTN Irancell and a widening loss at its e-commerce joint venture, Africa Internet Holdings.

In addition to its 49 per cent stake in Irancell, MTN said in May, 2017 it had agreed to invest more than $295 million in Iranian Net, a fixed line broadband network in which it planned to buy an initial 49 per cent stake.

MTN said its MTN Nigeria unit expected to list on the Nigerian Stock Exchange before the end of 2018.

According to pre-IPO documents seen by Reuters in February, the telecoms firm planned to raise at least $400 million to cut debt for its Nigeria unit, then valued at $5.23 billion.

MTN is seen as one of post-apartheid South Africa’s biggest commercial successes, but clashes with regulators in recent years have hobbled its growth.

It appointed Shuter about a year ago to put it back on growth trajectory.

He has drawn up a new growth blueprint that includes branching out of basic telecoms services into music streaming, mobile banking and e-commerce and is reviewing the company’s presence in markets where it is not a major player.