What's happening in Ukraine? Newsround guide
Ukraine has been in the news because it is at the centre of a big argument between the world's most powerful countries.
The disagreement, between Russia and the world's other big nations like the UK and America, is over a region in the south of Ukraine, called Crimea and parts of Eastern Ukraine.
There have been fights and protests in East Ukraine, as some people there want Ukraine to be part of Russia.
Now the Ukrainian army is fighting with Russian supporters in eastern parts of the country, and there are concerns it may lead to war.
May 2014: Votes
On 25 May, the country held a presidential election - though Russian supporters in eastern parts of the country tried to disrupt the voting.
Petro Poroshenko, a successful businessman who made his money by making sweets, claimed victory.
He said he would support an election for a new parliament later in the year.
On May 11 voting took place in parts of Eastern Ukraine to ask people there if they want to stay part of the country or rule themselves.
Referendums took place in Donetsk and Luhansk and organisers say that the results showed most people there want to be independent.
However, western governments and Ukraine's leaders in Kiev say the vote was illegal and does not count because it was not carried out properly.
Russia's leader Vladimir Putin says he supports the region's choice and recognises the results of the referendums.
Fighting and violence in Eastern Ukraine
At the moment, much of the fighting in Ukraine is over the east of the country - with warnings that Ukraine is about to enter a civil war.
In mid-April 2014 Pro-Russian protestors took over government buildings in parts of eastern Ukraine.
The Ukrainian government responded by sending in troops to try and remove the protestors.
Having troops from both sides in the area made it very tense, and some people worry the clashes could lead to war.
Ukraine has sent in their army because they are worried the same thing might happening to Eastern Ukraine that happened to Crimea...
March 2014: Russia takes over Crimea
Russian President Vladimir Putin sent thousands of soldiers into Crimea because he said he needed to protect Russian people who live there.
But western countries like the US, UK and France said that Russia's taken over the region, and that what Russia did was against international law.
Most of the people living in Crimea believe they are Russian, not Ukrainian.
Tensions grew when a group of armed men took over the government buildings there and raised a Russian flag.
They also held marches supporting Russia through the streets. Ukraine's new government saw this as a challenge to their authority.
On 28 February, Russia's parliament agreed to send troops to Crimea.
On 6 March MPs in Crimea voted to join Russia, and announced they would hold a referendum to let the public decide.
The Ukrainian government said this was against the constitution.
Of the people who took part in the vote, 96% chose to join Russia - but a lot of people did not vote.
Russia's president Vladimir Putin said the vote was fair, but leaders in Europe and the United States said the vote was illegal.
President Putin signed a treaty to make Crimea part of Russia on 18 March.
Why is Ukraine in such trouble?
Ukraine has had a violent few months that have caused some massive changes in the country.
From November 2013, big anti-government protests took place in the country's capital, Kiev.
Many people were very unhappy about how the country was being run, accusing many of those in charge of corruption.
Those protests became very violent. Dozens of people lost their lives and hundreds more were injured.
The violence began when police tried to remove protesters, but they stood their ground - both sides fought with force.
The unrest eventually led to big changes in the government and in February 2014 President Viktor Yanukovych was forced from power and fled the country.
A temporary president, Olexander Turchynov was appointed as well as a new prime minister and a temporary cabinet, with a presidential election planned for 25 May.
Why did the protests begin?
In late 2013, hundreds of thousands of protesters took to the main square in the capital Kiev over a row about Ukraine's position in Europe.
It started in November after President Yanukovych decided not to sign a major partnership deal with the European Union (EU).
What is the European Union?
The EU is a partnership between 28 European countries that work together to make laws and share money
Lots of the demonstrators support the EU and want Ukraine to be more friendly with other European countries.
Ukraine and the EU have been through years of talks to try and include the country in the partnership.
Not everyone wants closer ties with the EU; there are also large numbers of people, particularly in the east, who support Ukraine's close ties with Russia.
History between the nations
Ukraine used to be part of the Soviet Union, a group of states ruled from Moscow, in Russia.
But in 1991 the Soviet Union broke up and Ukraine became a country in its own right.
Since then there has been a kind of tug of war over how the country should be governed.