Four top Senate Republicans prodded President Joe Biden to provide Ukraine with long-range missiles to help its counteroffensive against Russia, saying only a small part of US stockpiles would be needed.

With Biden due to host Ukrainian President Volodymyr Zelenskiy at the White House next week, the plea to the president puts a renewed focus on the Army Tactical Missile Systems, or ATACMS, that Ukraine has long requested.

“Ukraine has significantly degraded Russian combat power and only requires a small portion of our stockpiled ATACMS,” senators Tom Cotton, Roger Wicker, Susan Collins and Lindsey Graham said in the letter dated Saturday.

While additional weapons deliveries are expected to be announced during Zelenskiy’s visit to Washington, ATAMCS aren’t on the list, according to a US administration official.

Ukraine’s push to regain Russian-occupied territory has been a slow grind. The senators said Ukraine’s military has “achieved some breakthroughs” and providing Lockheed Martin Corp.’s ATACMs would “maximize the likelihood of success in its current counteroffensive and follow-on operations.”

The US has provided some $44 billion in security assistance to Ukraine since Russia launched a full-scale invasion of its neighbor in February 2022.

Read more: Ukraine Needs More Than a $30 Billion Arsenal to Strike Back

Meanwhile, the US government is rapidly approaching its Sept. 30 federal budget deadline. Some House Republicans have threatened to throw a wrench into the negotiations if a budget deal includes more aid to Ukraine.

Biden’s national security adviser Jake Sullivan said the “basic vibe” among lawmakers that the country needs to come together to support Ukraine is as strong as a year ago in both parties.

“But of course, I acknowledge that there’s a difference between this Congress and the last Congress, and we’ll have to contend with that as we go through the discussions that will continue in the days ahead on how to get Ukraine the resources it needs,” Sullivan said Friday.

--With assistance from Akayla Gardner and Jenny Leonard.