Question: What is the part of the Republic of the Marshall Islands inwhich Roi-Namur is an island in its north part 

Context paragraphs:
Fishing industry in the Marshall Islands: The Republic of the Marshall Islands has a commercial fishery that targets bigeye ("Thunnus obesus") and yellowfin ("Thunnus albacares") tuna using pelagic longline fishing gear.  There were 55 longline vessels licensed to fish in the Republic of the Marshall Islands Exclusive Economic Zone (EEZ) in 2011, of which 4 were Marshall Islands-flagged and 51 were foreign-licensed vessels, including 22 Chinese-flagged, 16 Japanese-flagged, 11 Federated States of Micronesia-flagged, and 2 Taiwan-flagged.  The Japanese-flagged longliners land their catch in Japan; the other 39 vessels were domestically-based (i.e., based from the Marshall Islands seaport at Majuro, the State's capitol).  In 2011, the Marshall Islands longline fleet had reported landings of principal market species of 259 mt of bigeye tuna, 99 mt of yellowfin tuna, 37 mt of blue marlin, 7 mt of black marlin, 4 mt of albacore tuna, and 3 mt of broadbill swordfish (MIMRA, 2012).  Fresh chilled bigeye and yellowfin tuna is exported primarily to markets in the U.S., China and Canada, and frozen tuna and incidental market species are exported to China and marketed locally.

Battle of Kwajalein: The Battle of Kwajalein was fought as part of the Pacific campaign of World War II.  It took place from 31 January-3 February 1944, on Kwajalein Atoll in the Marshall Islands.  Employing the hard-learned lessons of the battle of Tarawa, the United States launched a successful twin assault on the main islands of Kwajalein in the south and Roi-Namur in the north.  The Japanese defenders put up stiff resistance, although outnumbered and under-prepared.  The determined defense of Roi-Namur left only 51 survivors of an original garrison of 3,500.

Ij Io̧kwe Ļo̧k Aelōn̄ Eo Aō: Ij Io̧kwe Ļo̧k Aelōn̄ Eo Aō , also known more simply as Ij Io̧kwe Ļo̧k , is the former national anthem of the Marshall Islands.  It became the anthem from 1979 when it was separated from the Trust Territory of the Pacific Islands, and it remained the national anthem when the Republic of the Marshall Islands gained its independence in 1986, until 1991 when Forever Marshall Islands became the new national anthem.

Atama Zedkaia: Leroij Atama Zedkaia (1931 – November 19, 2010) was the Marshallese paramount chief, or Leroijlaplap, of Majuro.  Leroij Zedkaia spearheaded the movement to break the Marshall Islands away from the rest of the Trust Territory of the Pacific Islands and form the independent Republic of the Marshall Islands.  She was also the mother of Jurelang Zedkaia, who has served as the President of the Marshall Islands from 2009 to 2012.  Leroij is a title by a female paramount chief, or Leroijlaplap, in the Marshall Islands.

Kwajalein Atoll: Kwajalein Atoll ( ; Marshallese: Kuwajleen ) is part of the Republic of the Marshall Islands (RMI).  The southernmost and largest island in the atoll is named Kwajalein Island, which its majority English-speaking residents (about 1,000 mostly U.S. civilian personnel) often called by the shortened name, Kwaj .  The total land area of the atoll amounts to just over 6 mi2 .

Roi-Namur: Roi-Namur is an island in the north part of the Kwajalein Atoll in the Marshall Islands.  Today it is a major part of the Ronald Reagan Ballistic Missile Defense Test Site, hosting several radar systems used for tracking and characterizing missile reentry vehicles (RV) and their penetration aids (penaids).

Operation Flintlock (World War II): Operation Flintlock was the campaign against the Japanese in the Marshall Islands in the Pacific theatre of World War II, from 31 January to 4 February 1944.  The operation involved the invasions of Kwajalein, Eniwetok, and Majuro atolls.  Admiral Nimitz, Commander of the U. S. Pacific Fleet, chose two islands in Kwajalein Atoll, Roi-Namur Island and Kwajalein Island, as primary targets in the U. S. invasion of the Marshall Islands.   Kwajalein Atoll contained communication and weather observation units and two Japanese airstrips on Roi-Namur and Kwajalein Islands, a seaplane base situated at Ebeye Island, a submarine base at Roi-Namur Island, and other Japanese installations scattered on various islands throughout Kwajalein atoll.   Kwajalein atoll, particularly Roi-Namur and Kwajalein Islands, were subjected to heavy bombardment.  This attack also sank a large number of Japanese ships in Kwajalein Lagoon.  Bitter fighting between Japanese forces and the U. S. 4th Marine Division on Roi-Namur, and the U. S. 7th Infantry Division on Kwajalein, resulted in a U. S. victory on 4 February 1944.  The attack of the Japanese in the Marshall Islands was the first US attack, and capture, of Japanese territory, since the land was held by Japan before the start of World War II.  The capture of Kwajalein Atoll during Operation Flintlock provided American forces with a base of operations that assured the recapture of the Philippines and eventually the fall of Japan.

Marshall Islands and the United Nations: The Marshall Islands joined the United Nations on September 17, 1991.  Although the Marshall Islands are sovereign, the Republic is bound by a Compact of Free Association with the United States.  The Marshall Islands show overwhelming support for the United States.  On 13 key issues in 2008, the Marshall Islands matched the vote of the United States 100% of the time.  In 2015, however, the Marshall Islands voted to condemn the US embargo over Cuba.  The motion at the United Nations was supported by 191 member states, with two votes against (the United States and Israel) and no country abstaining.

Marshall Islands War Memorial Park: The Marshall Islands War Memorial Park is a beachfront park located in Delap on Majuro Atoll, Marshall Islands.  The park was part of the U.S. Headquarters Command Center for the Marshall Islands, which was responsible for administering the Marshall Islands following World War II.  It was located next to the main U.S. airfield on the atoll until 1971, when a new airfield opened; it then became a collection point for World War II artifacts.  The park includes weaponry and vehicles, such as Zeros and large ammunition pieces, from throughout the islands.

Kili Island: Kili Island or Kili Atoll (Marshallese: Kōle , ) is an island of 0.93 km2 located in the Marshall Islands.  It is the temporary home of about 600 inhabitants who are descended from islanders who originally lived on Bikini Atoll.  They were relocated when they agreed to let the U.S. government temporarily use their home for nuclear testing in 1945.  Kili Island became their home after two prior relocations failed.  The island does not have a natural lagoon and cannot produce enough food to enable the islanders to be self-sufficient.  It is part of the legislative district of the Ralik Chain of the Marshall Islands.  The island is approximately 48 km southwest of Jaluit.  It is one of the smallest islands in the Marshall Islands.

Supporting paragraphs: Roi-Namur Kwajalein Atoll
Answer: Kwajalein Atoll