Russian Troops Amass Biggest Military Buildup Ever on Ukraine's Border

Josep Borrell, the High Representative of the European Union, said that Russian troops have amassed their largest military buildup on Ukraine's border on Monday, according to the Associated Press.

Borrell said that the Russian troop buildup consists of around 150,000 soldiers, although he declined to comment on where he got the number from.

"It is the highest military deployment of the Russian army on the Ukrainian borders ever. It's clear that it's a matter of concern when you deploy a lot of troops," Borrell said. "Well, a spark can jump here or there."

The amassing of Russian forces includes the establishment of military field hospitals and "all kinds of warfare," Borrell said, according to AP.

Tensions between the two nations have been high since Russia's annexation of Ukraine's Crimean Peninsula in 2014, resulting in fighting that has led to more than 14,000 deaths.

Borrell said that Ukraine's relations with Russia are not improving and has called on the country to withdraw their troops.

For more reporting from the Associated Press, see below:

Russian Military Troops
Russian troops take part in a drill on the Sernovodsky polygon close to the Chechnya border, some 260 kilometers from the south Russian city of Stavropol, on March 19, 2015. The Associated Press reported on Monday that Russian forces have amassed its largest military buildup on Ukraine's border ever. Sergey Venyavsky/AFP via Getty Images

Borrell said Monday that the condition of imprisoned Russian opposition leader Alexei Navalny was "critical" and that the 27-nation group would hold the Kremlin accountable for his health and safety.

Despite the worrisome developments, Borrell said after a virtual meeting of the EU foreign ministers that, "for the time being, there is no move in the field of more sanctions" to be slapped on Russia.

He also said there wasn't a request for a synchronized EU diplomatic move of expulsions in the standoff between EU member state the Czech Republic and Russia following Prague's accusation that Moscow was involved in a 2014 ammunition depot explosion.

Borrell's Russian troop estimate figure is bigger than the 110,000 estimate provided by Ukrainian Defense Minister Andriy Taran on Wednesday.

The EU has steadfastly opposed the annexation of Ukraine's Crimean Peninsula but has been unable to do anything about it.

Efforts to reach a political settlement have stalled and violations of a shaky truce have become increasingly frequent in recent weeks across Ukraine's eastern industrial heartland known as the Donbas.

Diplomats had expected there was little to no chance of immediate new sanctions on Moscow, but they now will seek to apply more pressure nevertheless through diplomacy.

And over the weekend, French President Emmanuel Macron said that while dialogue with Russia is essential, "clear red lines" carrying possible sanctions must also be drawn with Moscow over Ukraine.