WASHINGTON (Reuters) - The decision by some states, particularly large ones such as Texas, to opt out of the health insurance marketplace is making it harder for federal health officials to implement such exchanges, President Barack Obama said.

"I think it's harder, there's no doubt about it," Obama told reporters on Tuesday. "It puts more of a burden on us."

The state-based exchanges, created under the 2010 healthcare law, were designed to offer individuals a centralized place to buy health insurance policies for 2014. But a number of mostly Republican-led states have opted out, pushing individuals to the back-up federally run exchange.

(Reporting by Susan Heavey; editing by Jackie Frank)

(This story was refiled to add dropped words to quote in the second paragraph.)