When Ukrainian President Volodymyr Zelenskyy lands in Washington on Wednesday, he will come with one of his biggest requests, but he may not get the response he wants, Politico writes.

Zelenskyy's visit to the United States, where he is scheduled to meet with President Joe Biden and address members of Congress, came as a shock to senior U.S. officials and lawmakers alike. While there were rumors of a big event in Washington, no one knew the exact details of the Ukrainian president's arrival or plans.

Now that the face-to-face meeting has been confirmed, officials say they expect a confrontation over guns and an attempt by Biden and Zelenskyy to use the meeting to gain favor with the new Congress.

Behind the scenes, U.S. and Ukrainian officials had been planning the visit for weeks-just as Washington and Kiev were beginning one of the most intense disputes about the future of the war. During a Dec. 11 phone call, Biden invited Zelenskyy to Washington to discuss upcoming combat operations and ways his administration can continue to support Ukraine, a senior administration official told reporters.

Weeks before the call, U.S. officials had been in talks with their counterparts in Kiev and in Europe about what military support the U.S. would continue to provide to Ukraine to help it fight through the winter. Kiev has appealed directly to the Biden administration for better weapons, which they say could potentially lead to victory. But the U.S. is hesitant to disappoint Ukrainian officials.

The topic is expected to dominate a face-to-face meeting between Zelenskyy, his team and the Biden administration.

"He needs longer-range weapons to enable him to preempt an expected Russian offensive," said Bill Taylor, a former U.S. ambassador to Ukraine. "He needs immediate financial support to keep his government running, and he knows that Congress will make decisions on these items this week."

While the Biden administration has pledged to continue supporting Kiev in its efforts to fight Russian forces, U.S. officials have resisted providing any resources that would allow the Ukrainians to launch long-range missiles.

According to the source, during a meeting with Biden and his national security team, the Ukrainian delegation is expected to make another round of requests for army long-range tactical missile systems, or ATACMS, as well as Grey Eagle and Reaper drones.

But U.S. officials are not ready to budge. Biden's White House has flatly refused to send ATACMS. The costs are high, U.S. officials say. Sending long-range missiles to Kiev could provoke Putin to use even more deadly weapons inside Ukraine.

This U.S. indecision has worried Ukrainian officials and forced the top military leadership inside the country to seek help from others, including countries outside the Western alliance. The Ukrainians fear that they will be unable to advance on the battlefield this winter and will lose the momentum gained after Kherson.

Biden plans to announce Wednesday that he will give Ukraine more of the other weapons it has asked for.

The administration will unveil a new $2 billion military aid package that for the first time will include Patriot missile defense and direct attack ammunition kits that turn unguided bombs into precision munitions The package also includes $850 million worth of artillery and other munitions from existing U.S. stocks.

The Patriot delivery is a decision that surprised even Ukrainian officials. The Patriot system is a long-awaited reward for Kiev, and the Ukraine-designated version is designed to intercept ballistic missiles.

While the Biden administration does not believe that aid will cease completely, officials privately acknowledge that there are concerns that funding is likely to shrink and slow down in the coming months. Zelenskyy's visit, they believe, could be a bulwark.