Property of the United States Government at the time devoted to governmental uses, property of the State of Nebraska, any county, or the city, abutting upon and adjacent to the streets or parts of streets being improved or included within any improvement district authorized in sections 14-384 to 14-3,127, shall not be subject to special assessment, but the amount of the cost of such improvement which would otherwise be assessable against such property shall be paid from funds created and maintained for that purpose as provided by law and such property shall not be counted in determining the sufficiency of a petition or protest.