The White House said on Wednesday that it could take many months for the powerful American Abrams tanks that President Joe Biden promised to Kiev on Wednesday to reach Ukraine, Reuters reported.

Ukraine should be ready for when the weather improves and the Russian offensive accelerates, said the spokesman for the National Security Council of the White House, John Kirby.

He said Washington should be prepared to support Ukraine as long as necessary and that there is no indication that Russian leader Vladimir Putin intends to strike NATO territory.

John Kirby said today’s decision had been “weeks” in the making.

“There was a lot of diplomacy in today’s announcements,” Kirby said on CNN.

“The decision you saw today, both by Germany and the United States, was made several weeks ago as a result of many, many discussions with the Germans and our allies.”

Kirby also said it would likely take “weeks, not months” to complete the training plan on the M1 Abrams tanks, though he reiterated that acquiring the tanks and completing such training would take months.

President Joe Biden announced on Wednesday that the US will send 31 M1 Abrams tanks to Ukraine as part of a major effort by European allies to show they are still united against the Russian invasion.

Asked if Germany had forced him to change his mind about sending Abrams tanks, Biden said the idea from the beginning was to make the decision together with other nations.