The United States has warned Israel it may stop supplying the country with weapons unless the humanitarian situation in Gaza improves.

This is not the first time Israel’s major ally has threatened to turn off supplies. In May, US President Joe Biden said he would halt some shipments of weapons to Israel if an invasion of the southern city of Rafah went ahead. But Prime Minister Benjamin Netanyahu pressed on with the campaign – and the flow of US weapons continued.

The latest warning though, which says Israel has 30 days to improve the humanitarian situation on the ground, or risk violating US laws governing foreign military assistance, is a significant step up in pressure, suggesting US military aid could be in jeopardy.

While other countries have drastically reduced their military aid to Israel over the past year, the United States has not.

Here’s a breakdown of who supplies Israel with weapons:

The United States:

The United States is overwhelmingly the biggest supplier of arms to Israel. In 2023 69% of Israel’s arm imports came from the US, according to a report into international arms transfers by the Stockholm International Peace Research Institute (SIPRI). Germany was the second largest, providing 30%, followed by Italy with 0.9%. The UK, France and Spain were among other minor contributors.

The US-imported weapons “have played a major role in Israel’s military actions against Hamas and Hezbollah,” the think tank reported, noting that at the end of 2023, thousands of guided bombs and missiles were delivered from the US to Israel. F-35 and F-15 fighter jets were also delivered to Israel from the US in January 2024.

CNN analysis has identified multiple instances that US-manufactured munitions were used throughout the war, including in strikes that killed civilians. Recently, CNN found that US-manufactured 2,000-pound bombs were likely used in the Israeli attack that killed Hezbollah’s leader, Hassan Nasrallah, in Beirut.

The US also provides financial assistance to Israel, delivering over $130 billion in bilateral funding since 1948, according to the US State Department. In 2019, the two countries signed a Memorandum of Understanding that ensured the US would annually provide Israel with $3.3 billion from the Foreign Military Financing program, and another $500 million for missile defense.

Germany:

While in 2023, Germany contributed 30% of Israel’s weapons, that supply has significantly reduced over the course of 2024.

Earlier this year, the International Court of Justice rejected a request from Nicaragua to order Germany to stop supplying military aid to Israel. One of their key reasons was that German military aid to the country had fallen from approximately €200 million ($220 million) in October 2023 to €1 million ($1.1 million) by the time of the judgement in March.

But on October 10, German Chancellor Olaf Scholz said the country had not stopped providing Israel with arms, noting that Germany “(has) supplied weapons and we will supply weapons.” He added that weapons will be delivered to Israel “in the near future.”

Israeli security has historically been a core element of German foreign policy due to the Nazi Holocaust against Jews during World War II.

Italy:

Italy has provided helicopters and guns to Israel, according to the SIPRI, and is a partner of the F-35 fighter jet program, helping to manufacture parts.

However, Foreign Minister Antonio Tajani told local media in late January that Italy had stopped arms shipments to Israel since October 7 last year. Any deals signed before then were still being honored, SIPRI said.

Pagella Politica, an Italian monitoring organization, said Italian companies had sold arms worth almost $129 million to Israel in the decade to 2022.

The United Kingdom:

The British government says its “exports of military goods to Israel are low.” It said it granted licenses valued at $23.42 million in 2023. However, the UK has suspended some licenses to Israel for military equipment over the past year.

Foreign Minister David Lammy suspended around 30 licenses out of 350 to Israel upon the Labour government taking office in July, with an official assessment finding there was a clear risk that the weapons could be used “to commit or facilitate a serious violation of international humanitarian law.”

The suspensions impacted the supply of some parts for drones and F-35 fighter jets. However, the UK government did not suspend supply of material not used in the Israel-Hamas conflict – for example, for training purposes.

Spain:

In February, the Spanish Ministry of Foreign Affairs, European Union and Cooperation issued a press release noting that the government had not issued any arms sales to Israel since October 7 last year.

On October 11, Spanish Prime Minister Pedro Sanchez condemned what he described as an “unacceptable” Israeli offensive in Lebanon and urged the international community to stop arms exports to Israel.

“We are emphasizing the urgency for the Israeli government to cease its hostilities which are violating international law by invading a third country, in this case Lebanon, as well as International Humanitarian Law, as has even been questioned by the International Court of Justice,” he said.

France:

While France has historically provided Israel with arms, in recent weeks the relationship between the two countries has become strained as French President Emmanuel Macron called for an end to arms exports to Israel to try and push for a ceasefire in Lebanon and Gaza.

On October 5, Macron called for the complete suspension of the sale of arms “used in the war in Gaza,” and stressed that France had not been involved in their supply. According to SIPRI, its data does not show any French exports of major arms to Israel from 2019-23, but it notes that France did supply components for arms.

CNN’s Mia Alberti, Christian Edwards and Inke Kappeler contributed reporting.