MANAGUA, Nicaragua (AP) _ President Daniel Ortega said Thursday that the United States has a ''policy of state terrorism against Nicaragua'' that contradicts its statements on democracy, human rights and respect for law.

Ortega spoke at a swearing-in ceremony for members of the National Commission for Protection and Promotion of Human Rights. He said the alleged American policy ''puts at risk the security of the nations of the world and commits outrage against the human rights of Nicaraguans.''

''With a policy of this type,'' he said, ''the United States is defending institutionalization of terrorism in the world and gives the right to whatever group to carry out similar actions.''

Ortega's leftist Sandinista government recently has renewed its claims that the United States is preparing to invade this Central American country.

Over the weekend, Ortega said the government would take measures to protect itself. A few days later, some tanks and armored vehicles were moved into the capital of Managua.

The government is particularly upset that the U.S. Congress voted to continue non-military aid to anti-Sandinista Nicaraguan rebels, known as Contras.

The Reagan administration announced a trade embargo against Nicaragua on May 1 because of considers to be attempts by the Sandinista to spread revolution in Central America.