Senator Chris Murphy (D-Conn.) blasted the U.S. government on Tuesday for enabling the humanitarian crisis that's underway in Yemen—just before the U.S.-backed Saudi coalition bombed the airport in the nation's capitol of Sanaa, further blocking aid from getting to Yemeni civilians.

Showing pictures of children who are starving amid what U.N. officials have called the worst famine the world has seen in decades, Murphy told his Senate colleagues, "This humanitarian catastrophe—this famine…is caused in part by the actions of the United States of America."

"We have a responsibility to make sure that the coalition, of which we are a part, is not using starvation as a weapon of war," said Murphy. "This is a stain on the conscience of our nation if we continue to remain silent."

The bombing of Sanaa's airport is expected to worsen the impact of the Saudi blockade. The Saudis said this week that they plan to loosen the blockade but have yet to follow through. The coalition has closed many of Yemen's ports to ostensibly prevent weapons-smuggling from Iran to the Houthi rebels who are fighting the Yemeni government forces—and civilians have suffered the consequences.

In addition the famine, Yemenis are also suffering from what Oxfam has called the worst cholera outbreak in history, with at least one million expected to be affected by the end of the year, including 600,000 children. The blockade has prevented desperately-needed sanitation supplies from getting to aid agencies, making it impossible to prevent new cases as the medical community—in which many doctors and nurses have been working without pay since much of the healthcare system has been shut down—tries to treat those who are already sick.

In his speech on the Senate floor, Murphy added that the United States' contributions to the Saudi coalition have made actions like the bombing of Sanaa's airport possible.

"It is U.S. refueling planes flying in the sky around Yemen that restock the Saudi fighter jets with fuel, allowing them to drop more ordnance," said Murphy. "It is U.S.-made ordnance that is carried on these planes and dropped on civilian and infrastructure targets inside Yemen. The United States is part of this coalition. The bombing campaign that has caused the cholera outbreak could not happen without us."

The senator also spoke out on social media.