President Donald Trump and North Korea's leader Kim Jong-un stand on North Korean soil while walking to South Korea in the Demilitarized Zone (DMZ) on June 30, 2019, in Panmunjom, Korea. Brendan Smialowski | AFP | Getty Images

North Korea's Christmas gift for the U.S. may be a long-ranged missile, according to a MIT professor. Vipin Narang, associate professor of political science at MIT, told CNBC's "Squawk Box" that North Korean leader Kim Jong Un has been sending a message to U.S. President Donald Trump as Pyongyang tested more short-range missiles throughout the summer and fall than in any other year in its history. "The message was loud and clear. This was Kim Jong Un's maximum pressure campaign on President Trump. Like if you're not hearing me about changing your calculations and giving sanctions relief and security guarantee and getting rid of the hostile policy, I can show you what long-range missiles look like," said Narang.

'Re-nuclearization'

Narang noted that the isolated nation has been testing at facilities that were "supposedly dismantled." "And the significance of conducting tests at the sites that were taken down is re-nuclearization. He's reversing steps he's taken and this is a calibrated step," he added. In a Wednesday note, Eurasia Group's Asia director Scott Seaman wrote "tensions are rising more quickly than we anticipated ... odds of Trump and Kim cutting a denuclearization deal before the 2020 US election have decreased."

Reuters reported that the U.S. special envoy for North Korea, Stephen Biegun, urged Pyongyang on Monday to return offers of talks. He also dismissed Kim's year-end deadline and emphasized Washington's willingness to discuss "all issues of interest," according to Reuters. But looking ahead, Seaman does not seem to be optimistic for 2020, "The US will likely ramp up efforts to show it is coordinating closely with allies like Japan and South Korea and also talking with other key players such as China and Russia." Meanwhile, "Kim will likely try to outdo US diplomacy with his own overtures to China, Russia, and other countries," said Seaman.

Pyongyang's allies

China and Russia on Monday proposed the U.N. Security Council lift a ban on North Korea exporting statues, seafood and textiles, according to a draft resolution seen by Reuters. Narang said China and Russia likely want to formally remove the sanctions all together. That would allow Kim to rely on the economic and energy trade with the two nations, which seem willing to diplomatically back North Korea. But Narang said, ultimately "there's a line" for China and Russia, too. He said China's position seems to be "you can go back to testing missiles just don't test a nuclear weapon," explaining that appears to be Beijing's "red line."