In November 1999, Peru and Chile signed three agreements that put to rest the remaining obstacles holding up implementation of the 1929 Border Treaty. (The 1929 Border Treaty officially ended the 1879 War of the Pacific.) However in late 2005, a declaration of maritime borders by Peru's Congress set off a new round of recriminations with Chile, which claims that the maritime borders were agreed to in fishing pacts dating from the early 1950s.

In October 1998, Peru and Ecuador signed a peace accord to resolve once and for all border differences that had sparked violent confrontations. Peru and Ecuador are now jointly coordinating an internationally sponsored border integration project. The U.S. Government, as one of four guarantor states, was actively involved in facilitating the 1998 peace accord between Peru and Ecuador and remains committed to its implementation. The United States has pledged $40 million to the Peru-Ecuador border integration project and another $4 million to support Peruvian and Ecuadorian demining efforts along their common border.

In 1998, Peru became a member of the Asia-Pacific Economic Cooperation (APEC) forum, facilitating closer ties and economic relations between Peru and Asian nations.

Peru has been a member of the United Nations since 1949, and is a member of the Security Council. Peruvian Javier Perez de Cuellar served as UN Secretary General from 1981 to 1991.

Peru maintains 204 troops in peacekeeping operations in Haiti under the UN's MINUSTAH.