Washington -  Defence Secretary Jim Mattis has said that the US will "watch" Pakistan's choices on President Donald Trump's new Afghan and South Asia strategy to combat terrorism in its tracks.

Pakistan has opposed Trump's Afghan and South Asia policy, saying it ignored the country's sacrifices in the war against terrorism. But, Mattis during a visit to Kabul said the new strategy was "not exclusive of someone". It is inclusive for all responsible states that want to stop terrorism in its tracks and defend the innocent, he said.

Mattis said the South Asia strategy announced by the president in August was an opportunity for Pakistan. "I agree 100 percent with President Ghani that this South Asia strategy and this renewed commitment is an opportunity for Pakistan to engage in the counter terror campaign," Mattis told reporters at a joint news conference with Afghan President Ashraf Ghani, according to a Pentagon transcript.

Mattis said that the United States would "watch" Islamabad's choices. Ghani echoed Mattis' views.

NATO Secretary General Jens Stoltenberg agreed with both Mattis and Ghani, saying that this is a regional approach, which includes both Pakistan and India. Both of them have to be included in a mutual approach. He urged all countries in the region to support an Afghan-led and Afghan-owned peace process.

Mattis said India has been "very, very generous" in its development assistance to Afghanistan. India is committed to doing even more to help the people of Afghanistan, he said.

Responding to a question, Mattis reiterated that Russia and US-designated state sponsor of terrorism Iran continue to provide weapons and other military aid to Taliban jihadists in Afghanistan.

The Pentagon chief blasted Russia and Iran’s continued support to Taliban jihadists, echoing concerns previously expressed by US officials, including Gen Nicholson, who has also noted that Pakistan is assisting the terrorist group as well.

“Those two countries have suffered losses to terrorism, so I think it would be extremely unwise if they think they can somehow support terrorism in another country and not have it come back to haunt them,” declared Mattis, referring to Iran and Russia, reports the Wall Street Journal (WSJ).

Support from Russia and Iran is strengthening the Taliban and lending legitimacy to the jihadist organisation, notes the newspaper, citing unnamed US military officials. “That’s a lot more dangerous right now than what they’re providing in terms of material,” a military official told the WSJ.

Russia and Iran have conceded sharing information with the Taliban to fight their mutual enemy, the Islamic State, but both countries deny providing military assistance to the group.

Afghanistan’s neighbor Iran, which the US Office of the Director of National Intelligence (ODNI) recently said “remains the foremost state sponsor of terrorism,” has also dismissed accusations that it is providing sanctuary to the Taliban.

In December 2016, Gen Nicholson told Pentagon reporters that the United States is concerned about the “malign influence of external actors” in Afghanistan, such as “Pakistan, Russia, and Iran,” noting that the countries are assisting the Taliban.

The general explained: Russia has overtly lent legitimacy to the Taliban. And their narrative goes something like this: that the Taliban are the ones fighting Islamic State, not the [US-backed] Afghan government… this public legitimacy that Russia lends to the Taliban is not based on fact, but it is used as a way to essentially undermine the Afghan government and the NATO effort and bolster the belligerents.