Afghan President Hamid Karzai lashed out Wednesday at the United States over the opening of a Taliban office in Qatar, pulling out of security talks with U.S. officials and refusing to take part in peace talks with the Taliban that he said would only benefit "foreigners' strategies and goals."

In a statement issued Wednesday, Karzai's office said Taliban rhetoric about continuing to take the fight to Afghan and foreign fighters, even as the group pursues a political solution, was "completely in contradiction to the assurance that was given to Afghanistan by the United States of America."

He used similar justification for suspending security negotiations with the United States over the presence of foreign troops in Afghanistan past the scheduled pullout next year.

Krazai's office said "foreign powers" were behind Tuesday's opening of the Taliban office in Doha, Qatar -- where U.S. officials are expected to begin talks with the Taliban on Thursday, according to a source close to the talks who did not want to be identified.

And Karzai appeared to renew earlier claims that the Taliban and Western officials want to destabilize Afghanistan, saying the Taliban polices are "for the well of foreigners' strategies and goals."

In March, he appeared to accuse the United States and the Taliban of collusion, saying violent attacks by the group "show that the Taliban are serving the foreigners and are not against them."

He later walked the remarks back, saying they were misinterpreted.

Speaking Thursday in Berlin, U.S. President Barack Obama said he wasn't surprised by Karzai's response.

"We had anticipated that at the outset there were going to be some areas of friction, to put it mildly, in getting this thing off the ground," Obama said.

But he said that he believes Karzai remains committed to political reconciliation, and that he needs to be.

"We don't expect that it will be easy," Obama told reporters at a news conference with German Chancellor Angela Merkel. "But we do think ultimately we're going to need to see Afghans talking to Afghans about how they can move forward and end the cycle of violence so they can start actually building their country."

Karzai's statements come one day before the United States is scheduled to have its first formal meeting with the Taliban in the group's new Qatar office.

The Taliban opened the office Tuesday with a promise to renounce international terrorism and commit to peace negotiations, conditions the United States had set before it would support establishing the office as part of peace talks.

But a Taliban spokesman also said the group would continue its military campaign, a promise soon followed by the group's claim of responsibility for the death of four U.S. troops.

Karzai's office said Wednesday that his administration wants peace with the Taliban.

"But the messages of continuation of fighting which were sent out during the opening of the Taliban office in Qatar are completely in contradiction with the peace-wanting spirit of the government of Afghanistan," Karzai said.

He said Afghanistan's High Peace Council would not take part in the talks with the Taliban in Doha "until the process is completely left to Afghans."

The council also expressed frustration Wednesday about the name the Taliban had chosen for the office.

The council is willing to talk to the Taliban, but "not under the name 'Political office of Islamic Emirate,' " it said in a statement.

Karzai earlier Wednesday suspended talks with the United States over maintaining a troop presence in Afghanistan to help train Afghan forces past the scheduled 2014 pullout date for Western troops.

The agreement could provide the basis for any future NATO role in Afghanistan.

Karzai's decision to suspend those talks came a day after NATO-led troops transferred security responsibility to Afghan forces.

The Afghan government suspended the talks "in view of the contradiction between acts and the statements made by the United States of America in regard to the Peace Process," it said in a statement.

CNN's Masoud Popalzai and Michael Pearson also contributed to this report.