Several hundred Washington families are expected to benefit from a U.S. immigration rule change that was announced this week to speed up the process to keep American citizens together with their illegal immigrant spouses and children.

The legal director for the Northwest Immigrant Rights Project said on Thursday that it's too early to say how much time and effort the new rule will save families.

Before the rule change, which goes into effect March 4, many illegal immigrants had to leave the country before they could ask the federal government to waive a three-year- to 10-year ban from returning to their American families.

Under the new rule, a U.S. citizen can petition for a waiver while the non-citizens remain in this country waiting for a decision.