Lahore - The deputy chief of the Threek-e-Taliban Pakistan (TTP) has been killed in a US drone strike, the militant group said in a statement Monday, as Washington continues to intensify attacks along the Afghan border region.

Khalid Mehsud, deputy leader of the umbrella TTP, died after the pre-dawn strike in North Waziristan tribal agency on February 8, the militants said in the emailed statement.

The group's leaders have nominated Mufti Noor Wali Mehsud to take his place, the statement said, adding that Mufti Noor has "undeterring trust" in TTP chief Maulana Fazlullah.

US officials in Islamabad had no immediate comment. Much of the border with Pakistan's northwestern tribal areas is off-limits to foreign journalists, and strikes along the porous frontier are difficult to verify.

The TTP had been mounting unrelenting terror attacks across Pakistan for years, before being uprooted by the army through a series of military operations in the northwestern tribal areas along Afghanistan border.

The intensity of attacks decreased sharply after their basis were eliminated in Fata, but the militant group found refuge in border areas of Afghanistan from where they continue presenting a security challenge to Pakistan through sporadic cross-border attacks.

Pakistan has therefore been demanding the Kabul government and the US-led international forces to eradicate TTP elements from Afghanistan. The US strike killing Mehsud shows that Washington has started to pay some head to Islamabad’s calls finally.

The confirmation of Mehsud’s death comes as the US has massively stepped up its air offensive in eastern Afghanistan, targeting drug labs of different Taliban factions and Islamic State hideouts as President Donald Trump looks to the sky to force the insurgents to the table.

But Afghan Taliban and the IS militants have reacted violently, launching a wave of deadly attacks across the war-torn country, including in Kabul, in a devastating display of defiance.

Officials admit the US strategy is not without risk, and the longer it runs the more costs will accrue.

More bombing almost invariably means more civilian casualties, which could further mobilise Afghans against the United States.