The U.S. government will stop adding extra visa pages to existing U.S. passports beginning Jan. 1, the State Department announced Thursday. Previously, U.S. passport holders could buy an additional 24 pages when they ran out of space in their passports for necessary visa stamps. Within two months, however, they'll need to scrap the old passport and get a new one.

"The decision to discontinue this service was made to enhance the security of the passport and to abide by international passport standards," the State Department said in a statement. It added it had begun issuing 52-page passports, as an extra option in addition to standard 28-page books, in October 2014, "to mitigate the impact on frequent travelers."

The department would accept applications for the extra insert of 24 pages through the end of the 2015, it said, but after that U.S. passport holders would have to purchase new passports by mail. 

The State Department release did not specifically cite the terrorist attacks in Paris last Friday, in which 129 people were killed and more than 350 injured. Claims emerged in the wake of the attacks that the surge in refugees from Syria and other war-torn countries beyond the Middle East had allowed jihadists into Europe unchecked. A Syrian passport was found near the Stade de France -- the site of one of the attacks -- purportedly belonging to a refugee who had traveled into Europe through Greece.

The base cost of adding pages to an existing U.S. passport is $82, the State Department said. The base cost of renewing a passport is $110, while the cost of a new passport is $110 plus an "execution fee" of $25. Requirements for blank space in passports vary by country, but the standard requirement is typically at least two blank pages for travel.

Standard U.S. passports come with 28 pages, of which 17 are devoted to exit and entry stamps and visas. The larger passport books come with 52 pages, of which 43 are designated for stamps and visas.