Blinken to warn China over its support for Russia’s military during this week's visit

"We're prepared to take steps when we believe necessary against firms that ... severely undermine security in both Ukraine and Europe," the official told reporters ahead of Blinken's trip. 

"And I think we've demonstrated our willingness to do so regarding firms from a number of countries, not just China," he added. "At any rate, again, I think this will be a key issue of discussion while we're in Beijing."

U.S. allies in Europe are concerned about the implications of Beijing's support for Russia's war in Ukraine and "what it means for European security in particular, and then, of course, it will be up to China to determine its next steps," the official noted.

This will be Blinken's second trip to China after a high-stakes diplomatic mission to cool U.S.-China tensions in June last year.

During his visit to Beijing and Shanghai, Blinken is expected to meet senior Chinese officials, including Foreign Minister Wang Yi, according to the State Department. It remains unclear if the Secretary of State will meet Chinese President Xi Jinping.

When it comes to Russia's defense industrial base, China is "the primary contributor," Blinken said last week, following the G7 foreign ministers meeting in Italy.

"We see China sharing machine tools, semiconductors, other dual-use items that have helped Russia rebuild the defense industrial base that sanctions and export controls had done so much to degrade," he said.

"Now, if China purports on the one hand to want good relations with Europe and other countries, it can't on the other hand be fueling what is the biggest threat to European security since the end of the Cold War. "

Chinese firms are playing an increasingly key role in propping up Russia's struggling economy and boosting its military capabilities, including via the trade of goods for use on the battlefield in Ukraine, according to a CNBC analysis.

Data from last year seemed to suggest Beijing was providing militarily useful equipment such as drones, helmets, vests and radios, extending a lifeline for President Vladimir Putin's war against Ukraine. 

Blinken will also "discuss a range of bilateral, regional, and global issues," such as the crisis in the Middle East and China's provocations in the South China Sea, said the senior official.

Beijing claims almost the entire South China Sea as its own and has been in territorial disputes with Southeast Asian countries like the Philippines, Indonesia, Malaysia and Vietnam, among others. It has previously warned Washington not to interfere in China's territorial and maritime rights.

On the trade front, the two countries continue to battle for tech supremacy and just last week, China slammed U.S. investigation into its maritime, logistics and shipbuilding industries, calling the move a "mistake on top of a mistake."

The senior U.S official pointed out that Washington is realistic about its expectations on Blinken's visit in resolving key issues.

"I want to make clear that we are realistic and clear-eyed about the prospects of breakthroughs on any of these issues," he said.  

"But we will continue to use diplomacy to communicate our positions and policies, clear up misperceptions, and underscore that we will continue to take actions to protect our national security and economy."