Just three days before US President-elect Donald Trump returns to the White House, Russia and Iran have finally signed a “comprehensive partnership agreement,” a deal that had been in the works for months.

Russian and Iranian officials say the “comprehensive strategic partnership treaty” covers all areas -– from trade and military cooperation to science, education and culture. The 20-year treaty could be extended further.

Russia’s war on Ukraine has been dictated as much by events in the air as by territorial gains on the front line.

Russia's military on Tuesday said it would retaliate against Ukraine after Kyiv attacked Russian regions by firing six U.S.-made ATACMS ballistic missiles, six UK-made Storm Shadow cruise missiles and launching one of the biggest drone attacks to date.

The barrage appeared to be one of the largest recent assaults in Ukraine’s campaign to damage Russia’s war machine on its home territory.