Sen. Bernie Sanders (I-Vt.) is digging in on an effort to remove certain National Museum of American History gift-shop items because they aren't American-made.

In a letter to the director of the National Museum of American History on Tuesday, the same day President Hu Jintao visited the White House, Sen. Sanders wrote that he was particularly disappointed that the miniature statues of presidents were made in China.

"It appears that a museum owned by the people of the United States, celebrating the history of the United States, cannot find companies in this country employing American workers that are able to manufacture statues of our founding fathers, or our current president," Sanders wrote. "That is pretty pathetic! I was not aware that the collapse of our manufacturing base had gone that far."

Sanders wants all the products to be made by American companies. 

"Given the state of the American economy, I would urge the National Museum of American History to do its very best to find American companies to manufacture the products it sells," Sanders continued in the letter. "I believe that Americans from all over the country who visit our beautiful national museum would be very appreciative if you would move in that direction."

On Wednesday, Brent Glass, the museum's director, told ABC's The Note blog that while many of the gift-shop products are American-made, product affordability is a factor as well.

“We do, whenever possible, try to buy from U.S.-made manufacturers and we contract primarily with companies that are based in the U.S.," Glass said. "We have more than 400 vendors just at our museum that are American that we work with. And our buyers only attend American trade shows. But a lot of distributors carry products made domestically and internationally. We try to offer items to the public that are affordable, and many of those products come from other countries, not only China.”

Sanders also posted pictures of the statues on his website.