UNITED NATIONS - US Ambassador Nikki Haley on Tuesday said there was progress in talks with China on imposing what she termed as “pretty serious” new UN sanctions on North Korea in response to its first ICBM launch.

The United States has been locked in negotiations with China for nearly three weeks on a new raft of measures, and Haley said China was negotiating with Russia to win its backing for possible tougher sanctions.

“I think we are making progress,” Haley told reporters. “I think we are moving. It’s not as fast as I would like but these are pretty serious sanctions and so I think that there is a lot of thought going into this.”

The United States made a push at the United Nations for tougher sanctions after North Korea achieved a milestone in its military program with the July 4 launch of an intercontinental ballistic missile.

The effort hinges on getting China, North Korea’s main ally and trading partner, on board before the measures can be presented to the full 15-member Security Council. Asked about Haley’s remarks, Chinese Ambassador Liu Jieyi said “of course we are making progress.” “It requires time, but we are working very hard.” Haley told the Security Council the day after the launch that she hoped to present new measures in a few days, such as cutting off oil supplies, banning North Korean guest workers or imposing new air and maritime restrictions on North Korea.

Despite the delay, China is cooperating with the US drive for sanctions, Haley said, but a deal on new sanctions also involves securing cooperation from Russia. “I was pleased with the response that we got back (from China). We were waiting to see if it was going to be weak or strong and I think they showed some seriousness with it,” she said. “The true test will be what they have worked out with Russia.”

The Chinese ambassador declined to comment on talks with Russia, saying that all Security Council members will be involved in decisions about the new sanctions.

Russia maintains that the July 4 launch was not an ICBM, citing its defense ministry’s assessment.

Moscow has also argued that sanctions are not the answer to reining in North Korea, and that talks, as advocated by Beijing, were needed.

In all, six sets of UN sanctions have been imposed on North Korea since it first tested an atomic device in 2006, but two resolutions adopted last year significantly toughened the sanctions regime.