Zelenskyy comes to Washington, DC, with a long military wish list. But what could he ultimately get?

• Ukrainian President Zelenskyy is in Washington to meet with President Biden and Congress.
• Zelenskyy brings with him a long military wish list, though it's unclear what he will go home with.

When President Volodymyr Zelenskyy meets with President Joe Biden in Washington, DC later today, he is expected to have a considerable military wish list with him.

The visit — planned for weeks but a surprise to most onlookers — comes as Russia bombards vast swathes of critical infrastructure in Ukraine, and as Ukraine seeks to maintain its forward initiative after retaking the city of Kherson last month.

Biden is expected to unveil a $2 billion military aid package on Wednesday, likely to include a Patriot missile defense system, a senior administration official told The Washington Post.

It will also include a wealth of artillery, plus Joint Direct Attack Munition kits, which can turn unguided fighter jet bombs into guided ones, Politico reported.

Ukraine has, for months, been requesting a Patriot system to deploy against Russia's aerial bombardment. But it's only one of the weapons Zelenskyy is expected to press for in his meetings with Biden and others.

A person familiar with the discussions told Politico that Zelenskyy will also make the case for receiving long-range Army Tactical Missile System (ATACMS), as well as Grey Eagle and Reaper drones.

With a range of up to 190 miles, the ATACMS missile would help to give Ukraine the ability to strike far into Russian-held territory. But the US has long balked at providing them, fearing that long-range weapons would be too provocative for Russian leaders.

In May, Biden ruled out supplying any weapon that had the potential to strike at Russia itself.

In December it also emerged that the US had modified HIMARS systems that it had sent to Ukraine, to prevent them from being able to fire ATACMS.

Providing the Gray Eagle — one the country's most powerful drones — has also been a long-running sticking point for Biden, despite urging from US lawmakers.

The drone, which carries up to four Hellfire missiles and has a range of 2,500 nautical miles, would provide Ukraine with a major advantage over the Black Sea, lawmakers argued.

But the Biden administration is concerned that its sensitive technology could end up in Russian hands if one is downed.

In November, two unnamed officials told CNN that, like with the HIMARS modifications, the Pentagon is looking into ways to adjust the Grey Eagle to safeguard its technical secrets.

All these are slow-moving efforts, and granting each request brings with it a considerable time lag needed for transporting the weapon and training Ukrainian troops to use them.

There is an additional concern about funding future aid packages. While the Pentagon publicly states that it will maintain support for Ukraine "for as long as it takes," right-wing pressure against generous aid packages is gaining traction.

In anticipation of the GOP regaining control of the House in the midterms, House Minority Leader Kevin McCarthy said there would no longer be a "free blank check" for such spending in future. It's a message that has been vehemently echoed by some of the party's most vocal and far-right lawmakers, but will have little impact on today's announcements.

Zelenskyy will be hoping to return to Ukraine far from empty handed.