On Saturday, President Biden signed legislation to provide another $40 billion in US aid to Ukraine as the Russian invasion enters its fourth month.

Passed by Congress with bipartisan support, the bill deepens America’s commitment to Ukraine at a time when the future of the war is uncertain. Ukraine has successfully defended Kyiv and Russia has refocused its offensive on the east of the country, but US officials have warned that a protracted conflict is likely.

The funding is intended to support Ukraine through September, dwarfing the $13.6 billion in emergency measures previously provided.

The new legislation would provide $20 billion in military aid, ensuring a steady stream of advanced weapons is used to cripple Russia’s progress. There is also $8 billion in general economic support, $5 billion to address possible global food shortages due to the collapse of Ukrainian agriculture, and more than $1 billion to help refugees.

Biden signed the measure under unusual circumstances. During a visit to Asia, a US official carried a copy of the bill on a commercial flight for the president to sign, according to a White House official.

The logistics reflect a sense of urgency for the US to continue to support Ukraine, as well as the overlapping international challenges Biden faces. Even as he tries to realign US foreign policy to confront China, he continues to direct resources toward Europe’s biggest conflict since World War II.