More than 60 percent of defective Galaxy Note 7 smartphones sold in the United States and South Korea have now been returned and exchanged for new models, Samsung has claimed. In other words, 40 percent of the dangerous devices are still in consumer hands, almost four weeks after Samsung issued a global recall on the Note 7.

The new figures appear to show a slowdown in the number of successful exchanges in the United States. Samsung said last Thursday that half of the potentially explosive phones in the US had been taken in and replaced with new models, suggesting that the number of defective phones replaced had only increased by around 10 percent in five days. Because today's figure is combined with South Korean returns, it's not clear exactly what percentage of phones have now been returned in the United States, but the company previously said both countries have already replaced more than half of the dangerous Note 7 devices.

Samsung has offered financial incentives to South Korean retail stores selling the Note 7 in a bid to facilitate exchanges as fast as possible, rushing stock to the country's mobile providers, and reportedly giving them 20,000 won (around $18) per phone replaced. Stores in the country can earn another 20,000 won per phone if they manage to exchange more than 80 percent of the Note 7 devices previously sold before the end of September, the Korea Times reports.

South Korea is slow to exchange its Note 7 phones

Despite these incentives, the process of exchanging defective phones for new, non-exploding models is going slowly in Samsung's home country. The Korea Times says that it took Samsung five days to exchange half of the Note 7 stock previously sold, compared to both the US and Singapore, where 50 percent of phones were returned and exchanged in just two days. Singapore has been particularly speedy in returning defective Note 7 models, with more than 80 percent of customers participating in Samsung's exchange program in the 10 days it's been open.

Its recent battery controversy has been something of a blow to Samsung's reputation — and its share price — but the company says more than 90 percent of Note 7 buyers are still choosing to replace their potentially dangerous models with the updated version. According to reports last week, just 4 percent of Korean Samsung customers chose to get a refund on their purchase rather than receive an updated Note 7. Samsung's problem here, however, is how to get the remaining defective phones exchanged — if their owners haven't exchanged them already, even with the threat of explosion, when will they?