US federal agents and law enforcement officers have entered the Chinese consulate compound here along with locksmiths after the mission was shut down, amidst spiralling tensions between Washington and Beijing.

The Trump Administration ramped up its confrontation with China this week, ordering Beijing's consulate in Houston to close over concerns about economic espionage.

The Chinese consulate located in Houston's busy Montrose Boulevard for 40 years closed on Friday evening as the deadline set by the Trump administration to shut down the mission expired.

On Friday, the flag and the seal of the People's Republic of China were taken down from outside the Houston consulate. Early in the morning, the consulate staff was seen removing their belongings from the building.

After the Chinese diplomatic staff vacated the building, a number of black SUVs, trucks, two white vans and a locksmith's van entered the compound, CNN reported.

In Beijing, the Chinese foreign ministry said it has expressed strong dissatisfaction and opposition to the US law enforcement officers' "forced entry" into the consulate and lodged a diplomatic protest.

"China will make a proper and necessary response in this regard," the ministry said in a statement.

The Consulate in Houston is the building of the diplomatic consulate and is also China's national property, it said.

According to the Vienna Convention on Consular Relations and the Sino-US Consular Treaty, the US must not infringe on the premises of the Chinese Consulate in Houston in any way, the ministry said.

In a tit-for-tat move, China too on Friday ordered the US to close down its consulate in Chengdu. While ordering the closure, China had accused the US of interfering in its "internal affairs and harming national security interests."

In Houston, 40 minutes after the 4 pm eviction deadline passed, a man believed to be a State Department official entered the consulate, along with others, after a small back door was pried open, local media reported.

About an hour later, the fire department crew entered the building.

Trump administration officials provided further details on Friday regarding their decision on the Houston mission, claiming the diplomatic outpost was one of several across the country facilitating influence efforts on behalf of Beijing that the US government said veered into “the coercive or covert".

“The sum total of the Houston consulate's activities went well over the line of what we're willing to accept, and unless we disrupted it, it threatened to become even more aggressive in Houston and other Chinese consulates nationwide,” a senior Justice Department official told reporters on a briefing call organised by the State Department.

The Chinese consulate in Houston, Texas, was opened in 1979.

Apart from now closed the Houston consulate, an embassy in Washington and an office at the United Nations, China maintained consulates in four US cities -- Chicago, Los Angeles, New York and San Francisco.

Tensions between both nations have escalated in recent months over the Beijing's handling of the coronavirus pandemic, China's crackdown on its Uygur Muslims in Xinjiang and Beijing imposing a controversial national security law in Hong Kong.

US Secretary of State Mike Pompeo has alleged that the Houston consulate of China was “a hub of spying and intellectual property theft".

Top American officials had also accused the consulate in Houston of being part of Beijing's "espionage operations" in the US.

The US said in a statement that the consulate was ordered to close "to protect American intellectual property and Americans' private information."

The idea to close the Houston consulate emerged this spring after China interfered when US officials returned to the consulate in Wuhan to retrieve diplomatic materials, according to a senior State Department official.

Chinese authorities refused to let the US officials leave Wuhan with the pouches, saying they had to search them before leaving, an aggressive move that violates the Vienna Convention which governs diplomatic relations, CNN reported.

The encounter left Secretary of State Pompeo irate, the report quoted a State Department official as saying.