Trump gushes over 'very nice' Christmas letter from Putin amid mounting tension between the countries

President-elect Donald Trump on Friday fawned over a Christmas letter he received from Russian President Vladimir Putin.

The president-elect announced in a statement he received a "very nice letter" from the Russian president, and that Putin's "thoughts are so correct."

"I hope both sides are able to live up to these thoughts," Trump wrote, "and we do not have to travel an alternate path.

Trump did not make clear what such an alternate path would be, but the letter came amid increased tension between the two countries and as the two leaders both called for their nations to increase the capabilities of their nuclear weapons programs.

In the letter dated December 15, but released by Trump on Friday, Putin extended his "warmest Christmas and New Year greetings" to "his excellency Donald Trump" and offered "sincere wishes to you and your family of sound health, happiness, well being, success, and all the best."

"Serious global and regional challenges, which our countries have to face in recent years, show that the relations between Russia and the US remain an important factor in ensuring stability and security of the modern world," Putin wrote.

The Russian president continued: "I hope that after you assume the position of the president of the United States of America we will be able - by acting in a constructive and pragmatic manner - to take real steps to restore the framework of bilateral cooperation in different areas as well as bring out level of collaboration on the international scene to a qualitatively new level."

Trump's release of the letter came as US-Russia relations have tensed in recent days.

President Barack Obama spent much of his year-end press conference last week zeroing in on Putin and Russia, warning the country that the US "can do stuff" to it. US intelligence agencies have assessed that Russia was attempting to intervene through hacks with the goal of assisting Trump to victory.

On Wednesday, the Kremlin said communications between Moscow and the US had ceased.

And on Thursday, Putin boasted about the strength of his military, claiming it was more powerful than any potential aggressor. Trump just hours later said the US must "expand its nuclear capability" until "the world comes to its senses."

Here's the letter Putin sent Trump: