The UN declaring Jaish-e-Mohammed chief Masood Azhar a global terrorist demonstrates international commitment to rooting out terrorism in Pakistan and bringing security and stability to South Asia, the Trump administration said on Wednesday, expressing hope that Islamabad will take sustained and irreversible action against terror groups operating from its soil.

Welcoming China's decision to lift its hold on the proposal to blacklist the Pakistan-based JeM chief,  a senior Trump administration official during a conference call with reporters said after 10 years China has done the right thing by lifting its blockade.

"I think China seems to have understood that it was increasingly important that it's actions on the international stage on terrorism matched it's rhetoric,” the White House official said on the condition of anonymity.

Pulwama attack, the official noted was just the latest in the terrorist attacks that this “deadly group” has conducted.

"Designating Azhar demonstrates international commitment to rooting out terrorism in Pakistan and bringing security and stability to South Asia," the official said, adding that this designation is critically important and it was a long time coming.

This designation, the official said, is in line with Pakistan Prime Minister Imran Khan's stated commitment to crackdown on militancy inside Pakistan and his acknowledgment that prosperity and development in Pakistan is contingent on maintaining regional stability.

“So we acknowledged that this designation is a good step forward and we look forward to how Pakistan would use this international designation press forward on its own stated commitment,” the official said.

"The US will continue to monitor the situation in Pakistan to determine whether the recent positive statements from the prime minister will translate into irreversible steps” to end terrorist and militant safe haven inside Pakistan," the official said.

"All too often the world has seen a familiar pattern of Pakistan taking temporary steps against militants following immediately terrorist attacks, only to reverse those positive steps a few months later when the heat is off," the official said, adding that the history of the effort behind this listing demonstrates Pakistan has in the past been reluctant to divorce itself from terrorist proxy groups.

“China's willingness to shield Pakistan in these policies has been unhelpful to establishing regional stability. China acting on behalf of Pakistan has prevented the designation of Azhar on multiple occasions over the last decade,” the senior administration official alleged.

The official noted that this listing that will help to “avoid a re-escalation” of India-Pak tension, by holding Pakistan accountable on its international obligations.

"This designation serves as a forcing function for Pakistan, to implement their stated commitments to peace and stability and to rooting out terrorism from Pakistani soil."

“We have seen Pakistan taking some steps against Jaish-e-Mohammed following the Pulwama attack. However, there are additional steps that Pakistan could take to show an irreversible commitment and to permanently put these kinds of groups out of business,” the official said.

Lashkar-e-Taiba and Haqqani networks are the other two groups among others, the official said.

"These steps could include things like arresting leaders and disrupting their ability to communicate and travel and shutting down affiliated businesses like their charity wings," the US official demanded.

"We remain hopeful that Pakistan will continue to move in this direction and that today's designation will assist in that effort,” said the senior administration official.

Responding to questions, the two senior officials who briefed reporters did not give any insight into why reference to Pulwama attack was taken off from the final resolution.

The officials said they would not go into the internal deliberations at the UN Security Council.

“China probably came to the conclusion that it needed to do the right thing, be on the right side. And that it can no longer afford for the sake of its international reputation to continue blocking what it was so obvious that down this was a deadly group and that is leader is responsible for these deadly attacks,” the official said.

"China came to realise that it should match its action on international terrorism. This was the culmination of a 10 years process," the official said.