By Hamid Shalizi
KABUL (Reuters) - U.S. President Donald Trump's national security adviser met Afghan officials in Kabul on Sunday and said the new administration was weighing diplomatic, military and economic responses to its Taliban and Islamic State enemies in Afghanistan.
The adviser, H.R. McMaster, was making the first high-level visit by a Trump official. He spoke to ABC News' "This Week" programme in the United States.
On Thursday, the U.S. military dropped a GBU-43 Massive Ordnance Air Blast bomb, one of the largest conventional weapons ever used in combat, during an operation against Islamic State militants in eastern Afghanistan.
While military officials said the strike was based solely on tactical needs, it led to speculation that Trump's defence advisers are planning to escalate the war against militants in Afghanistan.
The strike was estimated to have killed nearly 100 militants and no civilians, according to Afghan officials, although this has not been independently verified.
Interviewed from Afghanistan, McMaster said the United States had a more reliable Afghan partner than before but at the same time had reduced the degree and scope of its effort in that country.
"Our enemy sensed that and they have redoubled their efforts and it's time for us, alongside our Afghan partners, to respond," he said.
Trump, who took office on Jan. 20, had asked U.S. officials, including some in the Treasury and Commerce departments, to work together to integrate the various political, diplomatic, military and economic responses available, McMaster said.
"We'll give him those options. And we'll be prepared to execute whatever decision he makes," he said.
McMaster met President Ashraf Ghani and other senior Afghan officials to discuss bilateral ties, security, counter- terrorism, reforms, and development, according to a palace statement.
McMaster praised anti-corruption efforts and assured Ghani that the United States would continue to support and cooperate with Afghanistan on a number of issues, according to the palace.
Ghani told McMaster that "terrorism is a serious issue for the security of the world and the region" and if serious steps are not taken it would affect "generations" of people, according to the statement.
Illicit drugs and corruption also top the list of threats to Afghanistan's security, Ghani told the visiting officials.
The Afghan government refers to both the Taliban and Islamic State as terrorists. Afghan forces have struggled to contain Taliban insurgents since most international troops were withdrawn in 2014, leaving them to fight largely alone.
At the peak in 2011, the United States had more than 100,000 troops stationed in Afghanistan.
Nearly 9,000 U.S. troops remain there to train and advise Afghan forces, provide close air support to soldiers on the ground and form a separate counter-terrorism unit that targets Islamic State, al Qaeda and other militant networks.
The top U.S. commander in Afghanistan has said he needs "several thousand" more troops to help the Afghans take on a resurgent Taliban and battle other insurgents, but no official plan has been announced.
(Writing by Josh Smith and Howard Goller; Editing by Adrian Croft and Richard Chang)