Lionel Messi is looking like his old self again.

After adapting slowly to his new club and league, the Argentina great finally delivered a complete performance in a Paris Saint-Germain shirt this week.

President Joe Biden said this week the U.S. would take a more direct role in diplomacy to address Vladimir Putin's concerns over Ukraine and Europe, part of a broader effort to dissuade the Russian leader from a destabilizing invasion of Ukraine.

But any negotiations to peacefully resolve Europe's tangled East-West rivalries will present minefields for the U.S. president.

Negotiations between Iran and world powers aimed at salvaging a tattered 2015 nuclear deal resumed in Vienna on Thursday, with tensions high after Tehran made demands last week that European countries strongly criticized. The talks' chairman said he detected "a renewed sense of purpose."

Diplomats from Britain, France and Germany had urged Tehran to come back with "realistic proposals" after the Iranian delegation made numerous demands last week that other parties to the accord deemed unacceptable. Last week's talks were the first in over five months, a gap caused by a new hard-line government assuming power in Tehran.

Israel's foreign minister arrived in Cairo on Thursday on a diplomatic visit aimed at strengthening ties and shoring up a tenuous cease-fire between Israel and Gaza's militant Hamas rulers.

Foreign Minister Yair Lapid met with Egypt's president, Abdel Fattah el-Sissi, and the country's foreign minister, Sameh Shokry, for talks that reflected budding ties between Egypt and Israel's new government. Egypt's intelligence chief also participated in the meetings.

Saudi Arabia's crown prince was visiting the United Arab Emirates on Wednesday, the second stop of his high-profile tour of Gulf Arab states aimed at fortifying the kingdom's traditional alliances as rival Iran resumes nuclear negotiations with world powers.

Mohammed bin Salman's tour kicked off just after the kingdom hosted its first ever Formula One race and as its first international film festival was underway — events showcasing Saudi aspirations to be a cultural stomping ground and sweeping social reforms following decades under ultraconservative norms.

Israel's Justice Ministry said Thursday it was closing an investigation into two police officers who shot dead a Palestinian assailant as he lay on the ground, accepting the officers' assertion that they acted in self-defense.

A Palestinian attacker on Saturday stabbed and wounded an ultra-Orthodox Jew outside Jerusalem's Old City. He then tried to stab the officers before being shot and falling to the ground. Video footage showed a paramilitary Border Police officer shooting the attacker when he was already lying on the ground.

Vaccine makers are racing to update their COVID-19 shots against the newest coronavirus threat even before it's clear a change is needed, just in case.

Experts doubt today's shots will become useless but say it's critical to see how fast companies could produce a reformulated dose and prove it works -- because whatever happens with omicron, this newest mutant won't be the last.

There's no clear-cut definition for when a pandemic starts and ends, and how much of a threat a global outbreak is posing can vary by country.

"It's somewhat a subjective judgment because it's not just about the number of cases. It's about severity and it's about impact," says Dr. Michael Ryan, the World Health Organization's emergencies chief.

On a moonless summer night in Hawaii, krill, fish and crabs swirl through a beam of light as two researchers peer into the water above a vibrant reef.

Minutes later, like clockwork, they see eggs and sperm from spawning coral drifting past their boat. They scoop up the fishy-smelling blobs and put them in test tubes.

Hajji Wali Jan brought a half-dozen plastic containers to the well in Kamar Kalagh on a recent Friday — one of the handful of days each week he and those who live on his side of this Afghan village ae allowed to use the water source.

When it was finally his turn, the 66-year-old filled one container, then a second. The stream of water from the spigot got thinner. He started on another container — but the thread of water tapered away and then stopped before the vessel was full.