Some Pentagon officials were taken aback that German officials were publicly admitting the link between the Abrams tanks and the Leopards, one official said, speaking on condition of anonymity to discuss internal deliberations. He added that officials had thought those communications would only be internal.
By Monday, officials said both Mr. Austin and General Milley were onboard with sending American tanks to Germany. To make the point — or to be seen making the point — Mr. Austin called Mr. Biden on Monday to recommend sending the Abrams tanks.
While some lawmakers had suggested the United States needed to send as few as a single Abrams tank to unlock the German Leopards, the Pentagon leaders said that made no sense. If the United States was going to send its most advanced tank system, it should send a battalion with “combat power,” one official said.
A Ukrainian battalion has 31 tanks, so that was the amount the United States agreed to send, Pentagon officials said.
Several details still need to be worked out. The Army has not yet decided which specific type of Abrams tanks it will deliver, Douglas R. Bush, an Army assistant secretary, told reporters on Wednesday.
The Army has tanks in its inventory that might need to be revamped — but they will not need to be built from scratch by General Dynamics. The Army has more than 1,000 Abrams tanks either ready to fight or in various states of partial construction that could be retrofitted for use in Ukraine.
The Army must decide between variants of the Abrams tanks that have different electronics and a different gun turret, Mr. Bush said, a decision to be made by senior Pentagon officials in the coming weeks.
Procuring the tanks will take months, officials said, giving the U.S. military time to train Ukrainian soldiers how to operate and maintain them. It was unclear whether training would take place in Germany, the United States or both, Pentagon officials said on Wednesday.
Eric Lipton contributed reporting.