A ceasefire between Iran and Israel has not ended the threat of cyberattacks from hacking groups supportive of Tehran, the FBI and federal cybersecurity officials warned Monday.

In a public bulletin, the authorities warned that hacking groups affiliated with or supportive of Tehran may still seek to disrupt or disable critical infrastructure systems in the U.S. such as utilities, transportation and economic hubs. Hackers may also target defense contractors or other American companies with ties to Israel, the agencies said.

U.S. President Donald Trump said Monday he was not offering Iran anything nor talking to it "since we totally obliterated" the country's nuclear facilities.

Iranian President Masoud Pezeshkian told his French counterpart Emmanuel Macron that Tehran halted cooperation with the U.N. nuclear watchdog due to what he called the agency chief's "destructive" behavior towards the Islamic republic, his office said Monday.

Russia launched its biggest aerial attack against Ukraine overnight, a Ukrainian official said Sunday, part of an escalating bombing campaign that has further dashed hopes for a breakthrough in efforts to end the 3-year-old war.

Russia fired a total of 537 aerial weapons at Ukraine, including 477 drones and decoys and 60 missiles, Ukraine's air force said. Of these, 249 were shot down and 226 were lost, likely having been electronically jammed.

Many of the world's nations are gathering starting Monday in Spain for a high-level conference to tackle the growing gap between rich and poor nations and try to drum up trillions of dollars needed to close it. The United States, previously a major contributor, pulled its participation, so finding funding will be tough.

The four-day Financing for Development meeting in the southern city of Seville is taking place as many countries face escalating debt burdens, declining investments, decreasing international aid and increasing trade barriers.

It's been a week since the United States pressed Israel and Iran into a truce, ending a bloody, 12-day conflict that had set the Middle East and globe on edge.

The fragile peace, brokered by the U.S. the day after it dropped 30,000-pound "bunker-busting" bombs on three of Iran's key nuclear sites, is holding. But much remains unsettled.

An Israeli strike on Tehran's Evin prison during this month's 12-day war killed at least 71 people, Iran's judiciary said Sunday, days after a ceasefire ended hostilities between the two arch-foes.

U.N. nuclear watchdog chief Rafael Grossi says Iran likely will be able to begin to produce enriched uranium "in a matter of months," despite damage to several nuclear facilities from U.S. and Israeli attacks, CBS News said Saturday.

Iran began a state funeral service Saturday for around 60 people, including its military commanders, killed in its war with Israel, after Tehran's top diplomat condemned Donald Trump's comments on supreme leader Ayatollah Ali Khamenei as "unacceptable".

Iran on Friday rejected a request by U.N. nuclear watchdog chief Rafael Grossi to visit facilities bombed by Israel and the United States, saying that it suggested "malign intent".