Turkish President Recep Tayyip Erdogan won reelection in a runoff Sunday, following a nail-biter first round two weeks earlier. Having secured another five years, Erdogan now faces a host of domestic challenges in a deeply divided country, from a battered economy to pressure for the repatriation of Syrian refugees to the need to rebuild after a devastating earthquake.

Here's a look at the challenges ahead.

Tensions between Serbia and Kosovo flared anew this weekend after Kosovo's police raided Serb-dominated areas in the region's north and seized local municipality buildings.

There have been violent clashes between Kosovo's police and local Serbs, leaving several people injured on both sides.

Two opposing visions for Turkey's future are on the ballot when voters return to the polls Sunday for a runoff presidential election that will decide between an increasingly authoritarian incumbent and a challenger who has pledged to restore democracy.

President Recep Tayyip Erdogan, a populist and polarizing leader who has ruled Turkey for 20 years, is well positioned to win after falling just short of victory in the first round of balloting on May 14. He was the top finisher even as the country reels from sky-high inflation and the effects of a devastating earthquake in February.

When Turks head to the polls on Sunday to decide a historic presidential election, the Kremlin will be hoping they give long-standing leader Recep Tayyip Erdogan a convincing victory, observers say.

The winner will have leverage over key areas for Moscow, such as Russia's large-scale military campaign in Ukraine, the war in Syria and the Kremlin's standoff with NATO.

Like the blue and yellow flags that popped up around the U.S. when Russia invaded Ukraine 15 months ago, U.S. popular support for Washington's backing of Ukraine has faded a little but remains widespread, a survey by the University of Chicago's Harris School of Public Policy and NORC shows.

It found that half of the people in the U.S. support the Pentagon's ongoing supply of weapons to Ukraine for its defense against Russian forces. That level is nearly unchanged in the past year, while about a quarter are opposed to sustaining the military lifeline that has now topped $37 billion.

Russia alleges that dozens of Ukrainian militants crossed into one of its border towns in its Belgorod region, striking targets and forcing an evacuation, before over 70 of the attackers were killed or pushed back by what the authorities termed a counterterrorism operation.

Ukraine denied any involvement in the skirmishes Monday and Tuesday, instead blaming two Russian groups that claim to be volunteers fighting alongside Kyiv's forces in an uprising against the government of President Vladimir Putin.

Turkish President Recep Tayyip Erdogan has remained in power for 20 years by repeatedly surmounting political crises: mass protests, corruption allegations, an attempted military coup and a huge influx of refugees fleeing Syria's civil war.

Now the Turkish people and economy are being pummeled by sky-high inflation, and many are still recovering from a devastating earthquake in February made worse by the government's slow response.

Syrian President Bashar al-Assad has returned to the Arab fold after more than a decade of isolation, eyeing reconstruction and aid from formers foes as the conflict grinds on.

Since the brutal civil war broke out in 2011, it has killed more than 500,000 people, displaced millions and devastated much of the country's infrastructure and industry.

The U.S. has once again buckled under pressure from European allies and Ukraine's leaders and agreed to provide more sophisticated weapons to the war effort. This time it's all about F-16 fighter jets.

Ukraine has long begged for the sophisticated fighter to give it a combat edge as it battles Russia's invasion, now in its second year. And this new plan opens the door for several nations to supply the fourth-generation aircraft and for the U.S. to help train the pilots. President Joe Biden laid out the agreement to world leaders meeting in Hiroshima, Japan, on Friday, according to U.S. officials.

One man is revered in Western capitals for standing up to Russia's full-scale invasion of his country.