Iran has passed a new proposal to Pakistani mediators to end the war with the United States, in the latest effort to break the deadlock in negotiations.

Iranian state media reported that Tehran handed the offer to Pakistan on Thursday night, to pass on to Washington, though its contents were not immediately clear.

The White House declined to comment on the new proposal, saying only that discussions continued.

Nevertheless, the new proposal was seen by Pakistan’s government as an outcome of its energetic back-channel diplomacy. Islamabad’s role switched in recent days to the lower-profile but urgent task of passing messages between the two sides after the momentum behind direct talks stalled.

Islamabad has said it believes a deal is within reach. But it faces an Iran that is in danger of overplaying its hand and a US administration that is seeking total victory rather than a compromise.

Pakistani officials say they are conscious that it is not only regional peace at stake, but the health of the global economy and the livelihoods of millions of the poorest people in the world – including in Pakistan, whose monthly energy import bill has almost tripled because of the war.