The development, which was first reported by Fox Sports, doesn't preclude the sides from revisiting the deal, but negotiations had reached a standstill by Friday night.
The teams agreed in principle Thursday to a trade that would have sent the Reds' second baseman to the Nationals for multiple minor league players, pending Phillips' waiving his no-trade clause, sources told ESPN.
Phillips had not approved the trade and was not expected to until the Reds worked out fair compensation for him to waive his 10-and-5 rights, a source said. Because Phillips, a 14-year major league veteran, has 10 or more years in the majors, including at least five with the same team, he has the right to reject any proposed trade.
On Thursday night, Phillips hinted that he had accepted that he will go to Washington, tweeting that he was going from the 513 (Cincinnati area code) to the 202 (Washington).
When Phillips signed a $72.5 million, six-year contract with Cincinnati in 2012, it was considered a hometown discount. Because he had no trade protection, he bought a home in Cincinnati and has been heavily involved in the community.
Phillips, 34, is scheduled to make $13 million in the coming season and $14 million in 2017.