Canadian Prime Minister Mark Carney said Sunday he had a constructive conversation with U.S. President Donald Trump about a potential trade deal, with negotiators set to work toward an agreement in the coming weeks as the countries seek to resolve their bitter trade dispute just days before the U.S. midterm elections.

Trump subsequently said both sides had "the concept" of a mutually beneficial deal.

Supermarkets in Sweden, Belgium, Luxembourg and Estonia were hit Monday by problems with freezers and fridges that apparently were caused by cyberattacks, forcing some to dispose of ruined food.

The problems follow a case last month in which attackers remotely took control of refrigeration systems in hundreds of supermarkets and independent stores across France, sending temperatures soaring.

Global shares were mixed and oil prices retreated Monday, falling sharply on renewed hopes for progress in diplomatic efforts between the U.S. and Iran.

U.S. futures advanced after U.S. stocks fell Friday to their worst day since June as investors dumped artificial intelligence-related and other technology stocks.

Belgian Prime Minister Bart De Wever handed in his resignation on Monday as a long-simmering budget crisis boiled over, but King Philippe has not yet decided whether to accept it.

De Wever, a conservative Flemish nationalist, took office determined to tackle heavily indebted Belgium's budget problems but failed to win the support of the other members of his five-party government for his proposals.

Paulina Netinan Nodjibougada knows Senegal is making history hosting the Youth Olympic Games, but with her family struggling to cover daily living expenses, the event feels distant from her concerns.

The 26-year-old accounting student said she is struggling to find work and cope with the rising living costs in the capital, Dakar.

The Middle East is braced for a possible return to all-out war. There are concerns that the United States, along with Israel, could strike Iran shortly after Tuesday's midterm elections in the U.S.

Two Iranian officials said their delegation had left Qatar after days of discussions but that messages with the U.S. continued to be exchanged through the mediator. The officials spoke on condition of anonymity due to the sensitivity of the talks.

The United Arab Emirates' presidential adviser said Sunday that his country hopes a diplomatic breakthrough in Qatar-led mediations is possible to avert a new round of confrontation between the U.S. and Iran.

The Iran war, which began on Feb. 28 with joint strikes by the U.S. and Israel followed by attacks by Iran on the Gulf nations, has made it "a watershed year" for the region and the world, UAE presidential adviser Anwar Gargash said at a security forum in Bahrain.

French authorities expressed relief Sunday after mass protests over rising living costs resulted in less violence than previous weekends. But police expect new demonstrations as high schools at the heart of the movement reopen Monday after their autumn break.

Germany faced its own challenges after nationwide protests Saturday ended with rioters attacking police and looting stores in some cities. Around Europe, hundreds of thousands joined overwhelmingly peaceful marches Saturday inspired by young people, despite scattered unrest.

Iran’s top diplomat said consultations with mediators are ongoing as diplomatic efforts try to avoid a return to all-out war, and the final outcome depends on answers provided by the United States to the “Iranian questions.”

In an interview shared on his Telegram channel, Abbas Araghchi said Iran hoped the U.S. would choose “diplomacy over other paths.” He said Iran was ready for both defense and diplomacy, depending on Washington’s “rationality."

Mass shootings over the Halloween weekend — largely in nightlife districts across the U.S. — left at least six people dead and dozens injured, officials said.

The deadliest violence occurred in Dallas, where a handful of shootings in the city's Deep Ellum neighborhood, a center of music and restaurants, killed four people and injured 15 others, police said.