(CNN) A senior Chinese diplomat will travel to North Korea on Friday as a "special envoy" of Chinese president Xi Jinping amid growing pressure on Pyongyang to curtail its nuclear and missile program.

The move comes after US President Donald Trump wrapped up his 13-day Asia trip, where he called for more diplomatic measures to be applied to North Korea, singling out China to do more.

But observers cautioned against any expectations of an imminent solution to the nuclear crisis, saying, if anything, the visit was another step in the warming of relations between the two formerly close allies.

"Everyone's looking for a breakthrough on the impasse over the nuclear missile program and obviously that's part of the mix but ... this looks more like the main focus is on improving the Xi, Kim channel somewhat and seeing what can be done," said John Delury, associate professor at the Yonsei University Graduate School of International Studies in Seoul.

Improving ties?

Chinese state media Xinhua reported Wednesday Song Tao, head of the International Liaison Department of the Central Committee of the Chinese Communist Party, would be visiting North Korea this week. The trip is the first time a senior Chinese official has visited North Korea this year.

According to Xinhua, Song will officially be informing the North Korean Workers' Party of the outcome of their Chinese counterparts 19th Party Congress in October, where Chinese President Xi Jinping was given a second term as leader and solidified his power.

Tong Zhao, a fellow at the Carnegie-Tsinghua Center for Global Policy in Beijing, said it was very likely the nuclear standoff would be on the agenda.

"(Still) even if he's going to discuss the North Korea nuclear program I don't think the position of either party, North Korea or China on this issue, would change significantly," Zhao told CNN.

"It could well be routine exchange of their long standing positions."

Delury said it would be important to see how Song was received in Pyongyang and how the visit was reported in North Korea's state media.

"If he meets Kim Jong Un, that would be a very strong message that North Korea is willing to improve the relationship with China but I would be surprised if that happens," he said.

"The way that the North Korean's report the visit, who he meets, and the tone of the reporting will tell us something about whether it was positive and some progress made, or whether it was a surly exchange."

'Catch up' time

China has repeatedly called for a de-escalation of tensions on the Korean Peninsula , including a freeze in the North Korean nuclear program in exchange for the halt of United States and South Korean military drills.

However, North Korea has been clear in its opposition to diplomatic talks that involve abandoning its nuclear program. Its uncompromising line has helped put its former close alliance with its neighbor China into a deep chill.

A brief exchange of official cordial greetings in early November, after the conclusion of China's Party Congress, appeared to show China and North Korea might be making efforts to repair ties.

President Xi and Kim Jong Un have not met in person, and with no top-level diplomatic visits announced between the two countries in 2017 until this point, Pyongyang and Beijing will need time to "catch up," said Delury.

"Even just at a basic level of getting a sense of where Kim Jong Un is at and what are the possibilities," said Delury. "We're in the very delicate stage and you need to get a read, you need to have lots of conversations. The Chinese channel is one of them."

Reopening diplomatic channels

While Delury said he saw Song's visit as a likely sign of improving ties between the two countries, Zhao was less sure, adding it could just be the North Koreans attempting to fend off stiffer sanctions.

"If the relationship gets worse China could very well take the very radical step to cut off oil exports to North Korea and that could mean real trouble for the regime," he said.

The United States was pushing hard for oil exports to North Korea to be cut off as part of strict new sanctions in September but China and Russia softened the new measures to only limit oil sales

US President Trump celebrated his "great relationship" with President Xi on his official Twitter account Thursday, days after calling North Korean leader Kim "short and fat."

The failing @nytimes hates the fact that I have developed a great relationship with World leaders like Xi Jinping, President of China..... — Donald J. Trump (@realDonaldTrump) November 15, 2017

While Trump's visit to Asia in November pushed a hard line on North Korea, calling repeatedly for collective regional pressure to end the nuclear standoff, experts said there was likely no real connection between the Chinese visit and the US leader's recent Asia tour.

"China (may have) decided to postpone the visit to North Korea until the conclusion of the meeting so China knew better about what to say to North Korea regarding the nuclear program," Zhao said.