While there's a lot of attention on what Ukrainian forces are doing in the Kursk region of Russia, that doesn't change the fundamentals on the main battlefield of the war in eastern Ukraine.

Here's how the Kursk invasion steps up stakes for both Kyiv and Moscow.

In early August, Ukraine launched an unprecedented invasion into Russia's border region of Kursk, seizing hundreds of square miles of territory.

Some military experts believe Ukrainian forces are now attempting to dig in.

Ukrainian troops, they've gained a foothold.

Russia is trying to hit back with air power to make up for its lack of manpower on the ground in the area.

But Ukraine has deployed air defense missiles to try to limit the impact of Russian air power.

Ukraine has also been using the US-made HIMARS rocket systems to target Russia's reinforcements and infrastructure.

Moscow said that the systems were used to strike at least one of the three bridges over the River Seim in the Kursk region.

Russian military bloggers claim Ukraine has destroyed or damaged all three.

Videos released by the Ukrainian military also show attacks on a Russian pontoon and units on the same river.

Military analysts say these attacks could potentially trap Russian forces between the river and the Ukrainian advance, as well as impact Russian logistics.

Some military experts say one of Kyiv's goals is to force Russia to relocate its troops from the front line in the north and the east, where Ukrainians have been struggling to contain Moscow's offensive.

Two weeks into the Kursk invasion, the Kremlin appears to have different priorities.

The Russians are mounting concerted efforts in several points along the front line, and they've made advances towards the logistical hub of Pokrovsk in recent weeks.

The city, with a pre-war population of some 60,000 people in the Donetsk region, is under increasing Russian pressure.

In mid-August, local authorities announced evacuation of civilians from Pokrovsk.

If the city falls, it will be the largest population center taken by the Russians since Bakhmut in May 2023.

Pokrovsk is a city that major roads run through, railways, which are then supplying Ukraine's troops in the east and enabling them to keep up the fight against Russian forces.

Losing Pokrovsk would sever a vital artery, supplying troops fighting in the city of Chasiv Yar, which lies on heights that hold the key to controlling the region.

Both Kyiv and Moscow struggle with manpower, and military analysts say both have to make high-risk choices.

US officials believe Russia will need more than 20,000 properly trained personnel to retake Ukrainian-held territory.

Even after withdrawing some of its military forces from less-critical fronts to fight in the Kursk region, Russia has yet to displace Ukraine's troops.

But it has intensified its offensive in eastern Ukraine.

Ukraine judges it can devote some of its best forces to its operation in Kursk without allowing Russian forces to break through in eastern Ukraine, while Russia is yet to divert significant forces to Kursk from its offensives elsewhere.

The following weeks and months will show whose gamble pays off.