Kabul has no plans to revive a peace process aimed at bringing the Taliban to the negotiating table after a four-nation effort earlier this year produced no results, the spokesman of Afghan President Ashraf Ghani has said.

The four-nation group - comprising Afghanistan, Pakistan, China and the United States - has met five times since January without the Taliban, which has refused to join any peace talks.

"There is no set time for another meeting of the group," spokesman Haroon Chakhansuri told The Associated Press news agency on Thursday.

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Chakhansuri's remarks reflect the Kabul administration's disappointment over what it has described as half-hearted efforts by neighbouring Pakistan to jumpstart the peace process.

Ghani has accused Pakistan of harbouring Taliban leaders, an allegation that Islamabad denies.

Afghanistan continues to suffer from "terrorist groups that operate from and have a support base in Pakistan", Chakhansuri said.

However, Omar Zakhilwar, the Afghan ambassador to Pakistan, said that Afghanistan is still ready to seize any opportunity that would bring peace in the country.

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"The Taliban has refused several times in the past to join the peace talks, whereas we are making any efforts possible to draw out a plan with the concerned parties in order to bring peace," Zakhilwal told Al Jazeera on Thursday.

"But if the Taliban continues to call for war, we are ready to face them and defeat them.

Earlier in July, US President Barack Obama announced plans to leave 8,400 American troops in Afghanistan at the end of his term - an increase from his previous plan, reflecting the difficulty of drawing down the US presence in the country.

The move was widely seen as acknowledging the deteriorating security situation since the 2014 withdrawal of most international combat troops.

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In response to Obama's announcement, Taliban spokesperson Zabihullah Mujahid told Al Jazeera: "Whether the US decides to keep [its] troops in Afghanistan or not, whether the numbers are more or less, we will continue to fight them."

"Nothing changes for us and nothing can scare us or stop us in achieving what we have been fighting for the past decade. We are stronger than ever and 8,400 troops cannot stop us. So its basically useless for them to make such decisions, a waste of time."