WASHINGTON - U.S. holiday retail sales this year grew at the weakest pace since 2008, when the nation was in a deep recession. In 2012, the shopping season was disrupted by bad weather and consumers' rising uncertainty about the economy.

A report that tracks spending on popular holiday goods, the MasterCard Advisors SpendingPulse, said Tuesday that sales in the two months before Christmas increased 0.7 percent, compared with last year. Many analysts had expected holiday sales to grow 3 percent to 4 percent.

In 2008, sales declined by 2 percent to 4 percent as the financial crisis that crested that fall dragged the economy into recession. Last year, by contrast, retail sales in November and December rose between 4 percent and 5 percent, according to ShopperTrak, a separate market research firm. A 4 percent increase is considered a healthy season.

Shoppers were buffeted this year by events that made them less likely to spend: Hurricane Sandy and other bad weather, the distraction of the presidential election, and grief about the massacre of schoolchildren in Newtown, Conn. The numbers also show how Washington's current budget impasse is trickling down to Main Street and unsettling consumers. If Americans remain reluctant to spend, analysts say, economic growth could falter next year.

In the end, even steep last-minute discounts weren't enough to get people into stores, said Marshal Cohen, chief research analyst at the market research firm NPD Inc.

"A lot of the Christmas spirit was left behind way back in Black Friday weekend," Cohen said. "We had one reason after another for consumers to say, 'I'm going to stick to my list and not go beyond it.' "

Holiday sales are a crucial indicator of the economy's strength. November and December account for up to 40 percent of annual sales for many retailers. If those sales don't materialize, stores are forced to offer steeper discounts. That boon for shoppers cuts into stores' profits.

Last-minute shoppers like Kris Betzold, of Carmel, Ind., embraced the discounts.

"We went out yesterday, and I noticed that the sales were even better now than they were at Thanksgiving," Betzold said Monday while shopping at an upscale mall in Indianapolis. Betzold said the sluggish economy prompted her and her husband to be more frugal this year.

Spending by consumers accounts for 70 percent of overall economic activity, so the eight-week period encompassed by the SpendingPulse data is seen as a critical time not just for retailers but for manufacturers, wholesalers and companies at every other point along the supply chain.

Sales declined by 3.9 percent in the mid-Atlantic and 1.4 percent in the Northeast compared with last year. They rose 0.9 percent in the north central part of the country.

The West and South posted gains of between 2 percent and 3 percent, still weaker than the 3 percent to 4 percent increases expected by many retail analysts.

Online sales, typically a bright spot, grew only 8.4 percent.