The United States condemned a violent crackdown on a peaceful anti-government demonstration in Kiev Saturday and called on Ukraine's leaders to respect their people's right to free expression and assembly.

"These are fundamental to a healthy democracy and the respect for universal values on which the United States' partnership with Ukraine depends," State Department spokeswoman Jen Psaki said.

The United States voiced concern over fresh unrest in Egypt after nearly 200 people were arrested Friday in a clampdown on Islamists protesting against a new law banning unauthorized demonstrations.

In Cairo, police used tear gas against hundreds of Morsi supporters who had gathered in front of one of the capital's presidential palaces. Gunshots could be heard as well.

U.S. military chiefs insist they will not change their operations despite a move by China to scramble fighter jets to monitor American and Japanese aircraft in Beijing's newly declared air defense zone.

But the State Department said U.S. commercial airlines should observe China's demand to be given notice of aircraft entering the zone, while stating that compliance "does not indicate U.S. government acceptance of China's requirements".

The White House insisted Friday it is "imperative" that the United States and Afghanistan sign a new security pact this year, after the Afghan president said it could wait until his successor is elected.

"We have long made clear that we need to get a Bilateral Security Agreement done this year," spokesman Jay Carney told reporters.

Albania confirmed Thursday it was asked by the U.S. to destroy Syria's chemical arsenal on its soil, as protesters gathered outside the parliament in Tirana to demonstrate against any such plans.

"We were contacted by the United States, but no decision has been made yet," parliamentary speaker Ilir Meta said late Thursday in an interview to Top Channel television.

The United States insists it has a shared interest in ending extremist violence after Islamabad accused Washington of scuttling efforts towards peace talks by killing Pakistani Taliban leader Hakimullah Mehsud in a drone strike.

Mehsud, who was under a $5 million U.S. government bounty, was killed when a drone targeted his car in a compound in North Waziristan tribal district on Friday.

Germany and the United States are to strike a two-way deal not to spy on each other in the wake of the diplomatic furore sparked by the Edward Snowden revelations, a German newspaper reported.

A delegation of German chancellery and intelligence officials reached the deal during talks at the White House this week, the Frankfurter Allgemeine Sonntagszeitung (FAS) reported in its Sunday edition.

The United States believes that Syria's large stock of chemical weapons will be destroyed on schedule by the end of June 2014, U.S. officials said Thursday.

"I am increasingly confident that we will be able to complete this task, the elimination of the Syria's chemical weapons program, within the target date of June 30th of next year," said Thomas Countryman, assistant secretary for international security and non-proliferation.

Several thousand protesters gathered Saturday in Washington to demand a new American law limiting the National Security Agency's surveillance programs seen as encroaching on private life.

The protest comes amid a widening scandal revealing sweeping U.S. surveillance on the communications of ordinary citizens and global leaders that has sparked outrage worldwide.

The United States called Thursday on the Democratic Republic of Congo and opposition rebels to end months of dragging negotiations and conclude a peace deal.

The talks in the Ugandan capital, Kampala, began on September 10, but have yet to make any real progress.