In a new challenge to the Ukrainian leadership, opposition leader Mikhail Saakashvili, the former president of Georgia, said Monday that Ukraine needs a new Cabinet and he’s ready to lead it.

The assertion from Saakashvili, a former ally of Ukrainian President Petro Poroshenko who has staged a series of protests against him, comes as the nation grapples with enormous problems.

A glance at the main challenges facing the ex-Soviet nation:

CONFLICT IN EASTERN UKRAINE

Regular skirmishes between Ukrainian troops and Russia-backed separatists are continuing in eastern Ukraine.

The conflict erupted in April 2014 following the ouster of a president who was friendly to Russia and Moscow’s annexation of Ukraine’s Crimean Peninsula.

The fighting has claimed more than 10,000 lives and devastated the regions that make up Ukraine’s industrial heartland.

The warring parties have been reluctant to observe a 2015 peace deal signed in the Belarus capital of Minsk that called for the withdrawal of heavy weapons and troops from the line of contact. The rebellious regions would get broad autonomy, and Ukraine would retake control of its entire border with Russia.

Talks about deploying United Nations peacekeepers to help enforce the Minsk deal have dragged on amid sharp disagreements between Russia and Ukraine over the possible mission. Fighting has lessened, but continues.

Related talks about exchanging hundreds of war prisoners have stalled because of differences over who should be included. Last week, Russian President Vladimir Putin promised to help persuade rebel leaders to speed up the deal, but it remains unclear if an exchange will happen any time soon.

CORRUPTION

There is a simmering anger against official corruption despite the government’s pledges to eradicate it.

Public frustration over endemic graft was a key factor behind the protests that ousted former Russia-friendly President Viktor Yanukovych in February 2014.

But progress on uprooting corruption has been slow under Poroshenko, and Ukrainians have become increasingly desperate. Ukraine’s Western allies also have been worried.

The European Commission urged the country this month to move quicker to set up a dedicated anti-corruption court. It said in a report that electronic declarations of assets submitted nearly a year ago by officials have yet to be analyzed.

POLITICAL CHALLENGES

Saakashvili declared Monday that Ukraine needs changes and said he’s ready to form a new Cabinet. He also has vowed to push for the president’s impeachment.

While Poroshenko will be certain to ignore Saakashvili’s statement, it raises the heat on the president, who has faced mounting resistance from former political allies like Saakashvili.

Saakashvili, who stepped down in 2016 a year after Poroshenko appointed him governor of Ukraine’s Odessa region, has led protests against Poroshenko, accusing him of stalling reforms and covering up corruption.

Poroshenko stripped Saakashvili of Ukrainian citizenship this year, but Saakashvili forced his way across the border from Poland in September.

Other political forces have teamed up against Poroshenko. They include former Prime Minister Yulia Tymoshenko’s bloc, the Self Reliance Party and several right-wing nationalist groups. They are calling for the quick creation of a top anti-corruption court and changes to electoral law.

As the political infighting has intensified, the National Anti-Corruption Bureau accused the son of the nation’s interior minister of embezzling state funds — charges he dismissed as politically driven. The bureau and the prosecutor-general’s office also have opened criminal probes against each other.