The U.S. Senate was meeting in a rare Sunday session, debating a $95 billion aid package for Ukraine, Israel and Taiwan.

Some right-wing Republican lawmakers, many of them aligned with former President Donald Trump, have voiced increasing opposition to sending more aid to Ukraine for its two-year fight against the Russian invasion, imperiling approval of the assistance even though most Democratic lawmakers are in favor, as is Democratic President Joe Biden.

Republicans have generally supported more aid for Israel’s war against Hamas militants, although many U.S. lawmakers, especially progressive Democrats, have vocally condemned Israel for the extent of its counteroffensive that Palestinian health officials say has killed more than 28,000 people in Gaza after the Hamas terror attack in October killed 1,200 in Israel.

Senate Republicans last week blocked advancing a measure that included the foreign assistance along with provisions to tighten restrictions at the U.S.-Mexico border to try to curb the flow of thousands of migrants from crossing into the United States each day. Trump opposed the border measure as not tough enough and Republican lawmakers followed his lead on the issue.

The Republican senators could still try to include some tough migration controls in the aid package although it is not certain whether they can reach agreement with Democratic lawmakers. If the Senate approves the legislation, its fate is uncertain in the House of Representatives, where Republican opposition to further Ukraine assistance appears even more pronounced.

“The failure of the United States Congress, if it occurs, not to support Ukraine, is close to criminal neglect,” Biden said last week. “It is outrageous.”

German Chancellor Olaf Scholz said, “Without the support of the United States, and without the support of the European states, Ukraine will have not a chance to defend its own country.”

The bill includes $61 billion for Ukraine, $14 billion for Israel, nearly $5 billion to support partners in the Indo-Pacific, including Taiwan, and other assistance.

The Senate Democratic majority leader, Chuck Schumer, said lawmakers in the chamber would stay in session “until the job is done,” although extra televisions have been brought in near the chamber so the legislators can watch some of the Sunday night Super Bowl, pro football’s annual championship game in the U.S.