BERLIN, Nov. 23 (Xinhua) -- Germany "deeply regrets" U.S. quitting from the Opens Skies Treaty, and remains committed to the international arms control agreement, while Russia said it will seek firm guarantees that the states remaining in the treaty fulfill their obligations.

"We deeply regret that the U.S. decided to take this step and is now doing it. Our stance on the treaty has not changed: we see it as an important part of the arms control architecture," Foreign Minister Heiko Maas said in a statement on Sunday.

The minister also said that Germany is committed to efforts to overhaul the treaty so as to improve its role in confidence building between its members.

The U.S. move to abandon the treaty on Sunday marked the end of a six-month notification process since the world's superpower submitted the notice of its decision to exit the treaty in May.

The treaty, which became effective in 2002, allows its 34 State Parties to conduct short-notice, unarmed reconnaissance flights over the others' entire territories to collect data on military forces and activities.

The United States and Russia have blamed each other for noncompliance with the treaty, having each put a few limits on flights over their territories: Hawaii and some other U.S. bases have been off-limits, as has Kaliningrad, among others, according to media reports.

The treaty is aimed at building confidence and familiarity among State Parties through their participation in the overflights. By 2019, over 1,500 Open Skies flights had been conducted since the deal entered into force, according to media reports.

"We will seek firm guarantees that the states remaining in the Treaty on Open Skies will fulfill their obligations, firstly, on ensuring the possibility of observing their entire territory and, secondly, on ensuring that the materials of observation flights will not be transferred to third countries that are not participants of the treaty," the Russian Foreign Ministry said in a statement on Sunday.

If other participants really want the treaty to continue to operate, and Russia remains a member state of the treaty, then they should, without delay, seriously think about what should be done to allay Russian concerns, the ministry added.