Marshall Islands
claims US territory of Wake Island

Martinique
none

Mauritania
Mauritanian claims to Western Sahara have been dormant in
recent years

Mauritius
Mauritius claims the Chagos Archipelago (UK-administered
British Indian Ocean Territory), and its former inhabitants, who
reside chiefly in Mauritius, were granted UK citizenship and the
right to repatriation in 2001; claims French-administered Tromelin
Island

Mayotte
claimed by Comoros

Mexico
prolonged drought, population growth, and outmoded practices
and infrastructure in the border region have strained water-sharing
arrangements with the US; nationals from Central America slip into
Mexico seeking work or transit into the US; undocumented Mexican
nationals continue to enter the United States

Micronesia, Federated States of
none

Midway Islands
none

Moldova
difficulties with the Transnistria region complicate
controlling border crossing and customs regimes with Ukraine,
despite concordance on 2003 delimitation and customs protocols and
OSCE assistance

Monaco
none