"maintain its commitment" is correct and can be used in written English.
It is commonly used when discussing the need for someone or something to uphold the promises or agreements made. For example, "The company must maintain its commitment to provide a safe work environment for its employees."
CVS said it could not "maintain its commitment to excellent customer service" if cashiers sat rather than stood.
First, it needs to maintain its commitment of providing a list of essential medicines free of charge at public facilities, aiming to fulfill the target of 100% availability for this list of medicines.
However, Washington should maintain its commitment to human liberty, endorsing it always and promoting it whenever possible.
It is imperative that the administration maintain its commitment to these two governments.
Rival agency Standard & Poor's urged the government to maintain its commitment to repairing the public finances.
"The government … will at all times maintain its commitment to racial equality".
Green campaigners were quick to call for the UK to maintain its commitments on climate change, irrespective of Brexit.
Mr. Berlusconi warned Thursday that Italy's credibility was on the line if the government failed to maintain its commitments.
The United States, Mr. Bush said, would stop aggression against South Korea, show "American power and purpose" in support of the Philippines, maintain its commitments to Taiwan and press forward with a missile defense system.
Asked during his Senate confirmation hearing whether the U.S. should maintain its commitments in the accord, the former Exxon Mobil Corp. chief executive said the 180-country deal allows the country to influence the necessary "global response" to climate change.
"The ABC consistently reviews programs at the end of each year to ensure it maintains its commitment to audience needs and expectations.
