In a surprise move, Afghan President Hamid Karzai appeared to pour cold water on the chances for an immediate security deal with the U.S., saying that because of the ‘mistrust' between him and Washington, any agreement should wait until his successor is elected.

“The agreement should be signed when the election is conducted, properly and with dignity,” he told the Loya Jirga, a council of Afghan elders Karzai convened to vote on approving the deal, according to a report in the Wall Street Journal.

“There is mistrust between me and America. I don't trust them, and they don't trust me,” he continued after he shared the contents of a letter President Obama sent him Thursday morning.

Karzai’s move comes just as both sides were reporting that they had finalized the language of the security agreement, ironing out contentious differences.

The deal is crucial for Pentagon and State Department planning because it would establish remaining U.S. troops levels after the 2014 drawdown has ended, as well as critical economic and military assistance.

Earlier this week, Karzai demanded a letter from Obama apologizing for U.S. “mistakes” in the war and recognizing the suffering the more than decade-long carnage caused to Afghans. Karzai was seeking the letter in exchange for dropping his objections to granting U.S. forces the ability to raid private Afghan homes in “exceptional circumstances.”

Obama sent Karzai a letter Thursday morning, but it did not include an apology or acknowledge any U.S. mistakes. When it comes to raiding Afghan homes, the president said U.S. forces have already imposed strict guidelines for such operations.

The letter was first released by officials in Kabul and then by the White House.

In the opening, Obama said he was “pleased we have reached an agreement” on the text of the security pact and said it represented a “strong agreement for both our countries, which provides the foundation to continue our cooperation to build a better future for Afghanistan.”

He also acknowledged Karzai's concern about limiting the impact of the conflict on the Afghan people, “with particular attention to the sensitive issue of the safety and privacy of people in their homes.”

“Over time and especially in the recent past, we have redoubled our efforts to ensure that Afghan homes are respected by our forces and that our operations are conducted consistent with your law,” Obama wrote. “We will continue to make every effort to respect the sanctity and dignity of Afghans in their homes and in their daily lives, just as we do our own citizens.”

It was not immediately clear whether Karzai's words were an emotional outburst at the end of a nationalistic speech in which he repeatedly criticized the U.S. or a serious disruption in the negotiations.

Karzai is slated to step down after Afghanistan's next presidential elections, which are scheduled in April. But the vote could be delayed as Karzai searches for a preferred successor.

U.S. officials had wanted a security agreement in place by now, and any delay will hamper U.S. plans to provide billions of dollars in much-needed funds and assistance to Afghan police and security forces, as well as programs the State Department views as critical to preventing the country from returning to Taliban control.