Microsoft accused U.S. Customs officials of refusing to follow a trade agency's order to block imports of phones made by Google?s Motorola Mobility unit. Redmond filed a motion in a U.S. court on Friday asking the U.S. Bureau of Customs and Border Protection to enforce the measure. The U.S. International Trade Commission said in May 2012 that Google's Motorola Mobility infringed a Microsoft patent for generating and synchronizing calendar items. It barred any infringing Motorola Mobility device from being imported into the United States.

All phones with Google's Android software are affected by the ban, Microsoft said. But Google said that it should have applied to only some Motorola Mobility Android phones.

That order was to have gone into effect 60 days after it was issued but, according to Microsoft's court filing, it still has not been enforced.

"U.S. Customs appropriately rejected Microsoft's effort to broaden its patent claims to block Americans from using a wide range of legitimate calendar functions, like scheduling meetings, on their mobile phones," Matt Kallman, a Google spokesman, said in a statement. "We're confident that the court will agree."

The case is Microsoft Corp. v. Department of Homeland Security, 13-1063, U.S. District Court for the District of Columbia.