Military power: Russia vs Ukraine
Considering the resources, the Ukrainian military force might fall short if faced with the substantially larger Russian force.
Ukraine has 1,100,000 active troops whereas the Russian military forces comprise of a whopping 2,900,000 troops.
The reserve forces of Russia are also much higher (2,000,000) compared to the 900,000 troops of Ukraine.
According to a BBC Report he disparity in the resources is stark with Ukraine having only 98 attack aircrafts, 34 attack helicopters, 2,596 tanks, 12,303 armored vehicles, and 2,040 towed artillery. And Russia has 1,511 attack aircrafts, 544 attack helicopters, 12,240 tanks, 30,122 armored vehicles, and 7,571 towed artillery.
BBC reports that in theory, Russian forces could aim to sweep across Ukraine from the east, north and south and try to remove its democratically elected government.
Russia also mobilised troops in Crimea, Belarus and around Ukraine's eastern borders.
However, Ukraine's forces have gained combat experience in the Donbass region in the east of the country, where they have been fighting Russia-backed separatists since 2014, and are highly motivated, reports Reuters.
The military has called up all reservists aged 18-60, reports The Guardian.
Beyond the regular army, Ukraine has volunteer territorial defence units and around 900,000 reservists. Most adult males have at least basic military training, so Russia could find itself facing stubborn and protracted resistance if it tried to capture and hold onto territory.
The military challenge would be incomparably higher than in previous wars Russia has fought since the Soviet Union's collapse, including in breakaway Chechnya in the 1990s and against Georgia in 2008.
Top US military official Mark Milley said the scale of Russian forces would mean a "horrific" scenario with conflict in dense urban areas.
That combination, and the sheer size of Ukrainian territory, means that even if Russia can outgun Ukrainian forces on a conventional battlefield, any military clash could lead to a protracted and bloody partisan conflict.
Military analysts say Ukraine's anti-aircraft and anti-missile defences are weak, leaving it highly vulnerable to Russian strikes on its critical infrastructure. They say Russia would also seek to use its superiority in electronic warfare to paralyse its adversary's command and control and cut off communications with units in the field.
What is the west doing to help Ukraine's military?
Western countries have stepped up arms deliveries to Ukraine, but Kyiv says it needs more. The United States has ruled out sending US troops to Ukraine to fight.
The United States has provided more than $2.5 billion in military aid since 2014, including Javelin anti-tank missiles, coastal patrol boats, Humvees, sniper rifles, reconnaissance drones, radar systems, night vision and radio equipment. Further supplies could include Stinger anti-aircraft missiles, small arms and boats, reports Reuters.
Turkey has sold Kyiv several batches of Bayraktar TB2 drones, which it deployed against Russian-backed separatists in eastern Ukraine.
Britain supplied Ukraine with a reported 2,000 short-range anti-tank missiles in January and sent British specialists to deliver training. It has also provided Saxon armoured vehicles.
Estonia said it was sending Javelin anti-armour missiles and Latvia and Lithuania are providing Stinger missiles. The Czech Republic has said it plans to donate 152mm artillery ammunition.
Germany has ruled out arms deliveries to Ukraine but is co-financing a $6-million field hospital and providing training
