As Pope Francis calls for days of prayer for Ukraine and asks those involved not to have a war, the tensions between Moscow and Washington continue to rise amid a ceasefire period between Russians and Ukrainians.

With the world's attention focused on what could lead to an armed clash between two super powers, diplomatic efforts have redoubled as each government reinforces its arguments and refuses to accept the demands of the other.

Likewise, in Europe, NATO members who support the U.S. position showed their public support for the Ukrainian government, while trying to establish better conditions to develop future political and commercial relations with the Russian government.

To better understand the circumstances surrounding the difficult situation, which threatens to bring war back to the old continent, here are five things to understand what is going on.

Amid negotiations that are not advancing, as each of those involved refuses to give in to the claims of the other, is reflected in the way Russia deploys men on the border just as shipments of weapons from the West arrive to support the Ukrainian government.

Both Washington and Moscow point to the possibility of an eventual attack that would force them to react. On the Kremlin side, it denounces persecution by NATO and sees its bases in Eastern Europe as threats. On the side of the Biden administration, it fears that Russia will attack under the pretext of wanting to protect its citizens amid the internal military conflict Ukraine is experiencing.

Russia is trying at all costs to prevent NATO from continuing to expand into Eastern Europe, as they consider it a threat to Russian sovereignty.

In 2008, both Ukraine and Georgia were offered membership in the organization, something Moscow vehemently rejects. Recently, Russia's deputy foreign minister, Sergei Ryabkov, pointed out that one of the conditions for his government not to have a conflict with its neighbor is that it never join NATO and that the alliance stop its operations in Eastern Europe.

Similarly, Russia seeks that no country deploy nuclear weapons just beyond its national borders.

For now, the United States and its allies are not considering agreeing to Moscow's demands, leaving open the possibility of war.

After both were part of the Soviet Union, relations have been problematic since the turn of the millennium. In 2013, the Kremlin prevented Ukraine from joining the European Union, which was followed by an invasion of the Crimean peninsula in southern Ukraine, which was annexed by the Russian government.

Likewise, Russia has been blamed for supporting Ukrainian separatist groups with affinity for Russia. The resulting internal military conflict has killed at least 14,000.

According to Russia, it has no interest invading Ukraine, and instead points to the West as the aggressor.

However, the governments of the United States and the United Kingdom have warned of the circumstances surrounding the crisis and have issued real warnings of the risk of a military conflict. Likewise, the Biden administration said weapons have been sent and troops are being prepared to respond with authority if Russia invades.

While the intelligence services report on the numerous forces deployed by the Russian government along the border, the Kremlin explained that they are only protecting their sovereignty from the threat posed by NATO movements near their territory.

Both the U.S. and U.K. governments are getting ready for a possible military intervention, something the European Union does not have a clear answer for yet as they continue to analyze what their response would be as a bloc in the face of an attack by Russia.

For now, one of the biggest threats to Russia in the face of an invasion of Ukraine, is that of economic sanctions, especially one that would disconnect its banking system from the international SWIFT system, the financial transaction identification system that interconnects banking around the world.

The long-awaited Nord Stream II gas pipeline, which Moscow plans to inaugurate in the company of Germany, would also suffer the consequences of a Russian invasion and its launch would be delayed.