Today, Aflac (NYSE:AFL) announced its operating earnings -- which excludes derivative income or losses as well as other adjustments -- fell by 2% from $790 million in the first quarter of 2013 to $774 million in the most recent quarter. As a result of fewer shares outstanding, its earnings per share stood flat at $1.69.

A substantial portion of Aflac's business is done in Japan, and the company highlighted a reason for the flat performance: the nearly 10% weaker exchange rate when converting Japanese yen to dollars. Excluding the impact of currency, the company notes its operating earnings per share would've increased by $0.10, or 6%.

"We are pleased with our overall financial results in the first quarter of 2014," noted the CEO and Chairman of Aflac, Daniel Amos, in the announcement. "Japan, our largest earnings contributor, generated strong financial results for the quarter. From a financial perspective, Aflac U.S. continued to perform well in the first quarter, although we remain disappointed with our sales growth."

In total, its pre-tax operating income in the U.S. rose by 8% to $303 million. As a result of the currency impacts, its Japanese operations saw its earnings dip by 6% to $933 million. However as Amos notes, new premiums written by its operations in the U.S. fell by 4.4% relative to the first quarter of last year.

Total earnings per share at Aflac plummeted by 16% from $1.91 in the first quarter of 2013 to $1.60. However, as previously mentioned, this includes the impact of derivatives and investments. In the first quarter of last year, it saw a gain of $60 million from these, versus a loss of $61 million in the most recent quarter.

"I want to reiterate that our objective for 2014 is to increase operating earnings per diluted share 2% to 5% on a currency neutral basis. We are pleased that our first quarter earnings per share were above our annual target," said Amos to conclude his remarks. "We continue to believe we are well-positioned in the two best insurance markets in the world."

Patrick Morris has no position in any stocks mentioned. The Motley Fool recommends Aflac. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.