Hyundai Motor and its sister company Kia both recorded double-digit growth in US sales in July, increasing by over 10 percent on-year, according to the data from the US units of the Korean carmakers.

The combined sales of the two carmakers came to 143,787 units in July, 12.1 percent up from a year earlier, Hyundai Motor Group said.

Strong demand for electric vehicles is seen as driving a surge in Hyundai’s sales volume in the US.

Hyundai sold a total of 72,857 units, 10.7 percent higher than the previous year. The figure included 6,330 of its premium brand Genesis models.

Additionally, its retail sales recorded 61,745 in July, increasing by 2 percent on-year, marking the highest-ever July performance.

Hyundai's eco-friendly vehicle sales, which include all-electric and plug-in hybrids, came to 15,392 units, soaring by 77.7 percent in the same period.

By model, the Santa Fe hybrid EV posted 205 percent on-year sales growth, with that of the Tucson plug-in hybrid increasing by 44 percent over the cited period. Sales of the Ioniq 5 rose 109 percent.

Currently, Hyundai's cumulative US sales stand at 461,140 vehicles this year, up 14 percent from the previous year.

Meanwhile, Kia's July volume recorded 70,930, jumping by 14 percent on-year. Its retail sales came to 66,485, up 13 percent from the previous year.

Based on the combined sales from Hyundai and Kia, sales of green cars reached a total of 26,498 units in July.

The figure was higher than the 26,187 units recorded in May, marking the largest-ever monthly figure. The share of its green car sales accounted for 18.4 percent of the two companies' entire sales volume.

According to the data from the US-based Automotive News outlet, Hyundai and Kia's combined market share in the US market in the January-June period this year came to 10.6 percent, up 0.3 percentage points from the previous year.

Its market share is anticipated to remain above the 10 percent range throughout this year amid solid demand for EVs in the US market.