The Pentagon announced a package of $2.5 billion (€2.31 billion) in military aid for Ukraine on Thursday, ahead of Friday's summit at the US Ramstein military base in Germany.

The package includes several military vehicles — 90 Stryker combat vehicles and 59 Bradley fighting vehicles — but no tanks.

It will also replenish Ukrainian stocks of ammunition, including for HIMARS rocket artillery systems, NASAMS air defense systems and the Bradleys' 25 mm cannon.

The aid comes as Western supporters pledge to boost weapons deliveries to Ukraine to help break Russia's entrenched lines, almost a year after Russian forces launched their most recent invasion of the country.

The new package brings total US military assistance to Ukraine to $26.7 billion since February last year.

Thanks, but no tanks

Conspicuous by their omission in the list of military gear to be sent to Ukraine were Abrams tanks.

Washington has said that the modern tank would be of little use to Ukraine due to their complex engines — which are similar to those found in jets — that would require frequent and complex maintenance and refueling.

However, the refusal to send Abrams tanks may have wider repercussions after German Chancellor Olaf Scholz said that Berlin would only send its own Leopard 2 tanks to Ukraine on the condition that Washington sends Abrams.

Germany has been under renewed and increasing pressure to provide — or allow allies to pass on their own — Leopard tanks to Ukraine which are considered some of the best in the world.

But amid a lack of popular support for such a move among the German public, Scholz's government has yet to be forthcoming.

Continued western support

Representatives from around 50 countries will gather together at the US military base of Ramstein in Germany on Friday to discuss continued military support for Ukraine, especially amid fears of a new Russian offensive in spring.

US Defense Secretary Lloyd Austin met with his newly appointed German counterpart Boris Pistorius on Thursday.

Germany is expected to announce its own new aid package at the Ramstein summit, but it is unlikely to include tanks. Poland and Finland have both said they are willing to send their own Leopard 2 tanks to Ukraine, but Germany holds the right of approval for any such moves.

Several European countries have recently announced plans to send armored vehicles, but the UK was the first to say it will send tanks to Ukraine.

The summit comes following pledges from Ukraine's partners that they will not abandon the defense of Ukraine against Russian aggression.