As the Indo-US nuclear deal goes through the motions, India was on Wednesday asked to sign the Comprehensive Test Ban Treaty by the UN organisation overseeing this non-proliferation measure.

While announcing that Iraq had signed the CTBT in New York on Tuesday, the Executive Secretary of the CTBT Preparator Commission Tibor Toth said India, North Korea and Pakistan must also become signatories to the treaty.

The three countries in the Asian region are also important for enforcing CTBT and therefore "we urge them to sign the treaty," Toth told reporters in Vienna [Images] on Wednesday.

The 45-nation Nuclear Suppliers Group will consider granting waiver to India on Thursday to enable India resume global nuclear commerce and take the nuclear deal with the US forward.

India has ruled out signing CTBT under any circumstances rejecting constant appeals and has not succumbed to any pressure.

Japan [Images] had early this month urged India to sign the CTBT and the Nuclear non-Proliferation Treaty.

New Delhi [Images] has maintained that it is not a signatory to the NPT or the CTBT as it has fulfilled all major conditionalities required for non-proliferation and has an impeccable record.

Pakistan has said it will not sign the CTBT unless India does so.

Toth said Iraq's action was an important step in the area of prohibition of  weapons of mass destruction taking into account the crisis over this issue in the past 15 years.

With Iraq coming on board, 179 countries have signed the CTBT.

Toth also urged those signatory countries who have not ratified the treaty yet to do so to enable its enforcement.

The UN's Comprehensive Test Ban Treaty Organisation on Wednesday said test moratorium by all nations would continue so that the door to nuclear-testing can be completely closed.

"CTBTO sincerely hopes that the nuclear test moratorium by the countries around the world continues so that the door to nuclear test can be completely closed," Annika Thunborg of the chief public information and legal and external affairs division told PTI.

India, although, not a signatory to CTBT had officially said that it would not prevent the treaty from entering into force, she said.

The CTBT can come into force only if 44 specific countries ratify the treaty.

So far 35 countries have ratified the treaty including Russia [Images], France [Images] and Britain. Those who have to sign to make the treaty come into force include USA, China, Egypt [Images], Israel, Iran and Indonesia. Both US and Russia have not tested since early 1990s and France and China have not tested since 1996.

After India and Pakistan conducted nuclear tests in 1998, it was only North Korea which had tested. "We want all tests to be banned completely," Thunborg said.