Apple sold more than 10 million iPhones this weekend, despite not being able to sell the iPhone 6 and iPhone 6 Plus in China yet.

Company Chief Executive Tim Cook said the company could have sold even more iPhone 6 and iPhone 6 Plus phones if supplies had been available, according to Reuters.

Analyst predicted first-weekend sales of at least 10 million iPhones, after Apple pre-orders for the devices reached 4 million on Sept. 12, the day pre-orders opened.

The company's first-quarter revenue should be 9 percent higher than Wall Street estimates, based on reported sales and projected demand for the new iPhones, iPhones, Piper Jaffray & Co analyst Gene Munster wrote in a note.

Munster said he expected earnings per share to be 12 percent higher than estimates.

"Despite the supply chain constraints around the iPhone 6 Plus and tightness around certain models of the iPhone 6, we believe (Monday's) strong print demonstrates that Apple executed extremely well in the face of severe supply constraints," Cantor Fitzgerald analyst Brian White wrote in a note, according to Reuters.

First-day pre-orders of the new phones easily surpassed the 2 million first-day pre-orders for the iPhone 5 model, which went on sale back in 2012. The iPhone 6 went on sale in 10 countries the first day pre-orders were available to consumers.

"While our team managed the manufacturing ramp better than ever before, we could have sold many more iPhones with greater supply and we are working hard to fill orders as quickly as possible," Cook said in a statement, according to Reuters.

Apple sold 9 million iPhone 5S and 5C models in 11 countries last year during the first weekend they were available.

Sales for the latest iPhone were hurt by regulatory issues. Shipment levels are positive overall though, considering the iPhone 6 and iPhone 6 Plus are not available in China yet.

Apple said the new iPhones will be available in 20 more countries on Sept. 26, and 115 countries by the end of 2014, according to a note by Stifel Nicolaus & Co analyst Aaron Rakers.

Many U.S. customers have to wait until next month for their iPhones due to strong demand.

During their first weekend, Apple sold 5 million iPhone 5 handsets, 4 million iPhone 4S models and 1.7 million iPhone 4 units, according to Reuters.

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