UKRAINE has imposed martial law after its president claimed Russia is preparing a "large scale" ground attack.

Petro Poroshenko made the shocking allegations in a live TV address to the nation as he revealed he is introducing the measure in order to "ensure security."

16 Ukraine has now signed a decree calling for martial law in the country Credit: Alamy Live News

He said he has "serious grounds" to believe Russia is ready to follow up the weekend's outrageous naval clashes in the Black Sea with a full-scale ground attack.

However, some critics say Poroshenko could be using World War 3 fears as a vote winner ahead of his country's elections.

Donald Trump tonight said the US would work with Europe to address the escalating tensions.

If the invasion news is true, it will send shudders down the spines who remember Russia's controversial annexation of the Crimea in 2014.

Back then thousands died in fighting between Ukrainian troops and the separatists. Many more found themselves homeless.

16 Poroshenko told his people he had evidence of a planned attack by Russia

What we know so far...

Ukraine president Petro Poroshenko claims Russia is preparing a ground invasion on his country.

He has introduced a month-long stint of martial law to ensure Ukraine's national "security".

Two Ukrainian artillery ships and a tug boat were fired upon by the Russians - in clashes which left six seaman injured.

The Berdyansk and Nikopol gunboats and the Yana Kapa tug tried to sail from Odessa to Mariupol in the Sea of Azov.

Russia scrambled two fighter jets and two helicopters to the area accusing the ships of illegally entering its waters.

The Ukrainian navy later said the boats had been hit and disabled as they tried to leave the area.

Donald Trump says the US would work with Europe to address the escalating tensions.

Ukraine's worried president called an emergency summit of his war cabinet after military tensions in the troubled region reached boiling point.

The move came hours after Russia fired on Ukrainian ships and captured 23 sailors sparking fears of war, with the UN and NATO both frantically arranging emergency meetings.

The British government condemned Russia's "act of aggression" adding: "It is further evidence of Russia’s destabilising influence in the region."

Trump said: "We do not like what’s happening either way. We don't like what's happening, and hopefully it’ll get straightened out.

"I know Europe is not, they are not thrilled.

"They’re working on it too. We’re all working on it together."

Ukraine's decree states "Martial Law in Ukraine will effective from November 26 to January 25, 2019." It was later cut back to a month.

The order could see the imposition of direct military control over the nation's people.

It could also mean control of TV stations, compulsory military service, a ban on demos and even a suspension of elections for the sake of national security.

Uefa is keeping an eye on the situation, but says Arsenal's Europa League tie with is still scheduled to go ahead.

16 Ukrainian activists of National Corps take part at their protest in front the Ukrainian Parliament Credit: Alamy Live News

16 Orphans strengthen trenches on Ukraine's Army positions near the village of Rybatske Credit: AP:Associated Press

The news comes after Ukrainian foreign minister Pavlo Klimkin warned it was likely "Russia plans further acts of aggression at seas or on the ground.”

The UN security council will hold an emergency meeting today to address escalating fears the Black Sea skirmish could lead to further military clashes.

Sunday’s hostilities began when Russia stopped three Ukrainian navy vessels passing beneath a bridge in the hotly-contested Kerch Strait.

Two artillery ships and a tug boat were subsequently fired upon and seized - in clashes which left at least six Ukrainian seaman injured.

16 The Nikopol gunboat, the Berdyansk gunboat, and the Yany Kapu tugboat (L-R) of the Ukrainian Navy tugged to the Kerch Seaport Credit: Getty - Contributor

16 Policemen guard at Russian consulate during a protest action in the Black Sea Ukrainian city of Odessa Credit: AFP or licensors

Russia said its patrol boats seized the vessels and crew after they entered its territorial waters illegally and carried out “provocative actions”.

“Their aim is clear - to create a conflict situation in this region,” Russia's hardline secret service the FSB said early on Monday.

However, Ukraine insists it had given Russia plenty of advance warning of the route being taken by its ships.

The incident, in waters off the Crimean Peninsula, marks a major escalation of tension between the two countries.

Each country blames the other for the worrying incident in which two gunboats and a tug were eventually captured by Putin's navy.

What is martial law? Martial law is the imposition of direct military control of the usual functions carried out by a government. It is usually introduced for a limited period and often as a reaction to either an emergency, major disaster or invasion. It gives authorities the power to limit public rallies and curb the media. Curfews are introduced, civil rights are suspended and military law is often extended to include the general public.

16 Ukrainian activists of National Corps take part at their protest in front the Ukrainian Parliament Credit: Alamy Live News

16 Ukraine's war council meets after the naval clashes with Russia off the Crimean peninsula Credit: EPA

Ukrainian Foreign Minister Pavlo Klimkin says the captured seamen should be treated as prisoners of war.

Klimkin told reporters in Kiev that the government is in talks with the Red Cross to make sure the seamen are treated as prisoners of war.

Six Ukrainians were injured after Russian border guards opened fire on three Ukrainian military vessels in the Kerch Strait on Sunday.

The vessels and the crews were captured by the Russians.

There have been growing tensions between the two sides over access to waters off the Crimean peninsula - annexed by Russia in 2014.

16 Martial law would ban all demonstrations on the streets of Ukraine Credit: AP:Associated Press

16 People attend a rally to support the Ukrainian navy in the Black Sea port of Odessa Credit: Reuters

16 Andrey Eyder, 18, is reported to be one of the sailors injured in the incident Credit: East2west News

16 Andrey Artyomenko, 24, was also reportedly hurt in the Black Sea clashes Credit: East2west News

The confrontation is a dangerous development in a conflict pitting Ukraine against Russian-backed rebels in the east of the country.

Thousands died in fighting between Ukrainian troops and the separatists during the annexation of the Crimea.

Under a 2003 treaty between Moscow and Kiev, the Kerch Straight and the Sea of Azov are shared territorial waters.

But recently, Russia began inspecting all vessels sailing to or from Ukrainian ports in the area.

16 The clashes occurred in the hotly-contested Kerch Strait

16 A protester prepares to hurl a smoke grenade outside the Russian embassy in Kiev Credit: EPA

However, the weekend's violence is the first time that Russian and Ukrainian fighters have officially clashed since 2014.

Now Ukrainian MPs are said to have voted to declare nationwide martial law following a plea by Poroshenko.

He insisted the move was not a declaration of war but intended for defence purposes - as his people took to the streets to protest at Russia's actions.

The confrontation is a dangerous development in a conflict pitting Ukraine against Russian-backed rebels in the east of the country.

Thousands died in fighting between Ukrainian troops and the separatists during the annexation of the Crimea by Russia in 2014.

16 Protesters chuck flares outside the Russian embassy in Kiev after three Ukrainian boats were seized Credit: Reuters

Russian ships block Ukrainian navy from entering Sea of Azov

Tensions between Russia and Ukraine have been building for months off the coast of Crimea.

Under a 2003 treaty between Moscow and Kiev, the Kerch Straight and the Sea of Azov are shared territorial waters.

But recently, Russia began inspecting all vessels sailing to or from Ukrainian ports in the area.

However, the weekend's violence is the first time the neighbouring country's fighters have officially clashed since 2014.

The US has already revealed it is ready to expand arms supplies to Ukraine to bolster the country's defence forces in the face of Russian pressure.

In May, Congress approved $250m in military assistance to Ukraine in 2019, including lethal weaponry.

Russian coastguard vessel 'Don' rams onto Ukrainian tugboat in the Black Sea in 'openly aggressive actions'

16 Two of Ukraine's small armoured artillery ships including the Berdyansk, pictured, were damaged before being seized Credit: Ukrainian Ministry of Defence

The European Union's executive urged Russia to release three Ukrainian ships it seized at the weekend near the Crimean peninsula that it annexed from Ukraine in 2014.

A spokeswoman stressed that the bloc does not recognise Russia's annexation of Crimea and said Russia was obliged to unblock the Kerch Strait swiftly.

"We are taking this very seriously," the spokeswoman said.

Nato also called on Russia to ensure unhindered access to Ukrainian ports in the Sea of Azov in accordance with international law, calling for calm on both sides.

Spokesperson Oana Lungescu said: “Nato is closely monitoring developments in the Azov Sea and the Kerch Strait, and we are in contact with the Ukrainian authorities.

"We call for restraint and de-escalation.”

MOST READ IN WORLD NEWS HAPPY MEAL McDonald’s worker pays customer’s bill after he calls mum to ask for her order Latest 'BIG FRIENDLY BEAR' First pics of sergeant shot dead at police station as pals pay tribute HERE WE SNOW! Leeds hit by SNOW as temps plummet to -5 as Brits brace for 65mph gusts today Exclusive HAPPY MEAL McDonald’s worker who paid for lad’s meal has secretly bought food for MONTHS BOMBER ALERT US B-52 bomber 'sends distress signal' after mid-air emergency in Gloucs EUGE NEWS Princess Eugenie 'so excited' to be expecting baby as Andrew & Fergie share joy

The vote on martial law comes four months before presidential elections that Poroshenko is expected to lose.

If Ukrainian MPs vote to suspend normal government, the elections could be postponed, prompting some to ask if Poroshenko is exploiting the incident

Russia's Deputy Foreign Minister Grigory Karasin has even said the Black Sea incident was premeditated.

"Obviously, it was a provocation, with its time, location and form premeditated," he said.

"The aims are clear: to shake Ukraine up via imposing martial law, and to mobilise the anti-Russian policies of the West, to step up the anti-Russian sanctions.

"Obviously, it is easier for Poroshenko to carry out his election campaign amid this background."