Ukraine will have to wait several months to receive the 31 M1 Abrams tanks promised by the United States because the Pentagon does not have enough critical vehicles in its own stockpile to ship them right now, Pentagon spokeswoman Sabrina Singh said, NYP writes. 

White House officials warned earlier that it could be up to a year before Kyiv receives the tanks that President Joe Biden has publicly promised because they will be purchased with funds approved by Congress as part of the Ukraine Security Assistance Initiative.

While it usually takes the Pentagon about four days to prepare and deliver weapons that come from the U.S. to Ukraine, the delivery of weapons under the USAI program, can take months or even years as the government searches for and hires defense contractors who produce weapons from scratch.

The U.S. announcement came the same day German Chancellor Olaf Scholz confirmed that his government would send 14 Leopard 2 battle tanks to Ukraine after weeks of hesitation and rumors that Berlin would not provide its tanks if the U.S. did not follow suit.

The Pentagon has previously expressed reluctance to send M1 tanks. On January 19, Singh stated that it just doesn't make sense at this point to provide [M1s] to the Ukrainians. At the time, she pointed to logistical problems with the U.S. tank because its gas turbine engine requires jet fuel, unlike the diesel engine used on the Leopard and Challenger.

Singh has now responded that she is not retracting her earlier comments, but denied that the Biden administration decided to use the USAI program to slow tank delivery.

Defense Department officials declined to say how many heavy combat tanks the U.S. currently has.  A senior White House official on Wednesday could not say exactly when the tanks would be ready for shipment.

The Pentagon has not given an exact timeline of how long it will take the defense industry to produce the 31 U.S. tanks, which are very sophisticated and weigh about 45 tons each.