WASHINGTON (AP) _ The State Department said Tuesday that high-level contacts with the Nicaraguan government produced progress in several key areas but that a suspension on U.S. aid to that country remains in effect.

Spokesman Richard Boucher said Nicaraguan officials offered assurances that they will accelerate procedures to permit the return to U.S. citizens of properties seized by the leftist Sandinista government that lost the 1990 elections.

He said 70 such cases have been resolved thus far.

Slow progress on the property question was one of several issues that led to a cutoff of $104 million in U.S. assistance to Nicaragua last June. An aide to Sen. Jesse Helms, R-N.C., who had pushed for the aid suspension, has written a report recommending that the assistance not be resumed until all properties belonging to U.S. citizens are returned.

The U.S. delegation that traveled to Managua was led by John Maisto, a deputy assistant secretary of state. The group met with President Violeta Chamorro and other senior Nicaraguan officials.

Despite losing the February 1990 elections, the Sandinistas have retained considerable influence in the Nicaraguan government, much to the annoyance of many U.S. conservatives.

The Bush administration, concerned about continued Sandinista domination of the Nicaraguan police, had been urging steps toward the creation of a non- partisan force.

Boucher expressed satisfaction with the recent appointment of a new civilian vice minister to be in charge of the police, calling it ''a positive step towards improving police performance.''

The vice minister, Ronald Aviles, is a longtime anti-Sandinista whose appointment was announced as part of a shakeup that included the naming of a Sandinista police chief, Fernando Caldera. The previous police chief also was a Sandinista.

The partnership between Aviles and Caldera could be uneasy. Aviles claimed he was jailed several times by Caldera during the 1980's when Caldera served as national police commander.

Another issue of concern to the Bush administration has been the unresolved murders of former members of the U.S.-backed Nicaraguan Contras. Boucher said the Nicaraguan government offered assurances that it will work closely with the Organization of American States to investigate these murders.

The Senate report said 217 former Contras had been assassinated since Chamorro took office in April 1990.