Since his first day in office, President Donald Trump has promised to “rebuild” the military by increasing the number of ships, aircraft and ground combat vehicles in the services’ inventory.

Yet defense officials have said the real work on that goal begins in 2018.

Trump’s budget for the current fiscal year calls for increases in troop numbers and some military equipment, but Defense Secretary Jim Mattis on several occasions has said the “real growth” in the military buildup begins with the fiscal 2019 budget, the first drafts of which will be unveiled in February.

“We didn’t get into this situation in one year, and we aren’t going to get out of it in one year,” Mattis said during congressional testimony in July. “We’re going to have to have sustained growth in [fiscal] 2019 to 2023.”

Congress still hasn’t settled on its fiscal 2018 appropriations for defense (or any other government departments) and is operating under a continuing budget resolution until Jan. 19. That means before officials can start debating a 2019 military buildup, they’ll have to fix the current budget problems first.

But lawmakers and White House officials have already provided some hints of the work to come. In the 2018 defense authorization bill, Congress called for big end strength increases, including 8,500 new soldiers, 5,000 new sailors, 5,800 new airmen and 1,000 new Marines.

Trump has also publicly promised a 355-ship Navy and at least another 100 combat aircraft for the Air Force.

But all of that will require congressional approval of billions more in defense spending during the next several years. Meanwhile, mandatory federal spending caps remain in place until fiscal 2021.

Trump’s past suggestions of cutting other domestic programs to pay for the increased military might have met fierce opposition from Democratic Party leaders and is a major reason why the fiscal 2018 budget is still unsettled.

The question is whether Trump, in his second year in the White House, will adopt different tactics to boost military spending or whether the same budget fights and fiscal brinkmanship will be repeated in the coming years.