Question: McCarran International Airport and Niagara Falls International Airport, are located in which country?

<P0-S0> McCarran International Airport (IATA: LAS, ICAO: KLAS, FAA LID: LAS) is the primary commercial airport serving the Las Vegas Valley, a major metropolitan area in the U.S. state of Nevada. <P0-S1>  It is located in Paradise, about 5 mi south of Downtown Las Vegas. <P0-S2>  The airport is owned by Clark County and operated by the Clark County Department of Aviation. <P0-S3>  It is named after the late U.S. Senator Pat McCarran, a member of the Democratic Party who contributed to the development of aviation both in Las Vegas and on a national scale. <SEP> <P1-S0> The Niagara Aerospace Museum is an aviation museum located in Niagara Falls, New York, in the old terminal building of the Niagara Falls International Airport. <P1-S1>  Formerly known as "Niagara Aerospace Museum", the museum was located in the Niagara Office Building in downtown Niagara Falls and relocated in 2008. <SEP> <P2-S0> The Niagara Frontier Transportation Authority (NFTA) is a public authority responsible for the public transportation oversight of Erie and Niagara counties in the state of New York. <P2-S1>  The NFTA, as an authority, oversees a number of subsidiaries, including the NFTA Metro bus and rail system, the Buffalo-Niagara International Airport, the Niagara Falls International Airport and NFTA Small Boat Harbor. <P2-S2>  The NFTA Metro bus and rail system is a multi-modal agency, utilizing various vehicle modes (diesel bus, diesel-hybrid bus, CNG bus, light rail and cut-away van), using the brand names: NFTA Metro Bus, NFTA Metro Rail, NFTA Metrolink and NFTA PAL (Para-transit Access Line). <P2-S3>  In addition, the NFTA also owns and manages a number of properties, including the Buffalo Metropolitan Transportation Center in Downtown Buffalo (which serves as the agency's headquarters); the Niagara Falls Transportation Center on Factory Outlet Blvd. the Portage Road Transit Center in Niagara Falls; and a number of strategically located bus loops and transit centers in the Buffalo Niagara region. <P2-S4>  Of note, many of the bus loops have been in continuous operation since the days of the International Railway Company, a predecessor to the NFTA. <P2-S5>  Agency-wide, the NFTA employs 1,500 full-time and part-time employees. <P2-S6>  There are three business centers that operate as the NFTA organization: Surface Transportation, which handles ground transportation throughout Erie and Niagara counties, Aviation, which handles air related business at the Buffalo-Niagara International Airport and Niagara Falls International Airport and Property Risk/Management, which operates the NFTA-Boat Harbor and handles other properties that are owned and/or operated by the NFTA. <SEP> <P3-S0> Niagara Falls International Airport (IATA: IAG, ICAO: KIAG, FAA LID: IAG) is 4 mi east of downtown Niagara Falls, in Niagara County, New York. <P3-S1>  Owned and operated by the Niagara Frontier Transportation Authority, the airport is a joint civil-military airfield and shares its runways with the Niagara Falls Air Reserve Station. <P3-S2>  A new terminal building opened in 2009.