(In first paragraph, changes number of countries to seven from six)

WASHINGTON, Jan 31 (Reuters) - Roughly 900 U.S. State Department officials signed an internal dissent memo critical of President Donald Trump's travel ban for refugees and immigrants from seven Muslim-majority countries, a source familiar with the document said on Tuesday.

A senior State Department official confirmed that the memorandum in the department's "dissent channel" had been submitted to management.

White House spokesman Sean Spicer said on Monday he was aware of the memo but warned career diplomats that they should either "get with the program or they can go."

(Reporting by Lesley Wroughton; editing by Diane Craft)

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