The pair of cities that have both a seaport and an international airport are Lagos and San Francisco.
Lagos is the largest city in Nigeria, located on the coast of the Atlantic Ocean, and it is home to the Lagos Port Complex, which is one of the largest and busiest ports in Africa. Lagos is also served by the Murtala Muhammed International Airport, which is the main airport in Nigeria and serves as a hub for many airlines.
San Francisco is a city in California, United States, located on the coast of the Pacific Ocean. The city is served by the Port of San Francisco, which is the fourth largest port in California and handles a variety of cargo, including containers, automobiles, and dry bulk. San Francisco is also served by the San Francisco International Airport, which is one of the busiest airports in the United States and a major gateway to Asia and the Pacific.
Kampala and Mombasa, Rio de Janeiro and Johannesburg, and New York and Warri do not have both a seaport and an international airport. Kampala is the capital city of Uganda, located inland and does not have a seaport. Mombasa is a port city in Kenya located on the coast, but its airport, Moi International Airport, serves only domestic and regional flights.
Rio de Janeiro is a coastal city in Brazil, known for its beautiful beaches and famous landmarks. The city has a seaport, the Port of Rio de Janeiro, which is one of the busiest ports in Brazil, but its airport, the Rio de Janeiro/Galeão International Airport, serves mainly domestic and regional flights.
Johannesburg is the largest city in South Africa and a major economic hub on the African continent, but it is not located on the coast and does not have a seaport. The city is served by the O.R. Tambo International Airport, which is the busiest airport in Africa and a major hub for international flights.
New York is a major city on the East Coast of the United States, located on the Atlantic Ocean, and is home to the Port of New York and New Jersey, one of the largest ports in the world. However, its main airport, the John F. Kennedy International Airport, is an international airport that serves numerous destinations worldwide, but it does not have a seaport nearby.
Warri is a city in Nigeria, located in the Niger Delta region, and is home to the Warri Port, which is one of the major ports in Nigeria. However, its airport, the Osubi Airstrip, is a small airport that serves only domestic flights.