The United States and Germany have both overcome reluctance and are set to send tanks to Ukraine in what will be an important boost in its fight to fend off Russia.
A decision by the US to send around 30 M1 Abrams tanks could be announced today, though it could take months for the tanks to be delivered, after a reversal by the Biden administration over sending the armoury.
US officials have said details are still being worked out with one stating that the tanks will be bought under an upcoming Ukraine Security Assistance Initiative package, which provides longer-range funding for weapons and equipment to be purchased from commercial vendors.
At the same time German Chancellor Olaf Scholz is to agree to sending Leopard 2 tanks to Ukraine, according to an official, with the decision not yet made public.
By agreeing to send the Abrams at an as-yet unspecified time under the assistance initiative, the US administration is able to meet Scholz's demand for an American commitment without having to send the tanks immediately.
Much of the aid sent so far in the 11-month-old war has been through a separate programme drawing on Pentagon stocks to get weapons more quickly to Ukraine. But even under that programme, it would take months to get tanks to Ukraine and to get Ukrainian forces trained on them.
Meanwhile, Anatoly Antonov, the Russian ambassador to Washington, has called the move by the US a "blatant provocation".
He wrote on Telegram: "If the United States decides to supply tanks, then justifying such a step with arguments about 'defensive weapons' will definitely not work. This would be another blatant provocation against the Russian Federation."
Until now, the US has resisted providing its own M1 Abrams tanks to Ukraine, citing extensive and complex maintenance and logistical challenges with the high-tech vehicles. Washington believes it would be more productive to send German Leopards since many allies have them and Ukrainian troops would need less training than on the more difficult Abrams.
Just last week, Under Secretary of Defence for Policy Colin Kahl told reporters that the Abrams is a complicated, expensive, difficult to maintain and hard to train on piece of equipment. One thing Defence Secretary Lloyd Austin has been very focused on, he said, "is that we should not be providing the Ukrainians systems they can't repair, they can't sustain, and that they, over the long term, can't afford, because it's not helpful."
The administration's reversal comes just days after a coalition of more than 50 senior defence officials from Europe and beyond met in Germany to discuss Ukraine's war needs, and battle tanks were a prime topic.
Ukrainian leaders have been urgently requesting tanks, but Germany had resisted mounting pressure either to supply its own tanks or clear the way for other countries, such as Poland, to send the German-made tanks from their own stocks.
On Sunday, Berlin indicated it wouldn't stand in the way if other countries wanted to send the Leopard 2 tanks to Kyiv. Germany needs to agree for the tanks to be given to Ukraine, which is not a member of NATO.
US and German officials have given mixed signals about whether the countries' decisions are linked, and if Berlin was hesitant to send its tanks unless the US sent Abrams.
Scholz is due to deliver an address to parliament Wednesday and field questions from lawmakers, many of whom have been pressing the government to join allies in providing the tanks to Ukraine.
