A Republican-led committee is probing cities that have limited their cooperation with federal immigration enforcement, often known as sanctuary cities. Boston is among them.

The city has been singled out as one of the nation’s four most problematic sanctuary cities and Mayor Michelle Wu has been asked to testify about its “sanctuary policies” at a public hearing next month,

Boston Mayor Michelle Wu said Tuesday that she will go to the nation’s capital to testify about Boston’s designation as a sanctuary city.