Secretary of State John Kerry said Sunday that “all options are on the table” after the Kremlin directed a military invasion of Ukraine’s Crimean peninsula, and the major world powers are “going to isolate Russia” in response to Russian President Vladimir Putin’s aggression in the region.

“This is an act of aggression that is completely trumped up in terms of its pretext,” Kerry said on NBC’s Meet the Press, adding that the United States and Western leaders are prepared to respond with economic sanctions, asset freezes and visa bans on Russia for its actions in Crimea.

Russian troops invaded the peninsula Saturday, capturing the capital and deploying troops across the Ukrainian peninsula, where ethnic Russians represent a majority of civilians.

(PHOTOS: Crisis in Crimea: Unrest in Russian Stronghold)

Western leaders are prepared to isolate Russia if it doesn’t de-escalate tensions, Kerry said. “Russia has major investment and trade needs and desires. I think there’s a unified view by all of the foreign ministers I talked with yesterday, all of the G-8 and more, that they’re simply going to isolate Russia, that they’re not going to engage with Russia in a normal, business as usual manner, that Russia is inviting opprobrium on the international stage.”

“There could even be, ultimately, asset freezes, visa bans. There could be certainly disruption of any of the normal trade routine. There could be business drawback on investment in the country. The ruble is already going down and feeling the impact of this,” Kerry continued.

Congress should begin working on sanctions immediately, the Secretary of State said in a separate interview on ABC’s This Week, as well as on an aid package to Ukraine. “The hope of the U.S. and everybody in the world is not to see this escalate into a military confrontation.”

Kremlin-directed troops surrounded Ukrainian military bases and dug trenches to hold Crimea, even as Ukrainian troops mobilized on directions from Kiev. The situation escalated Sunday, as pro-Russia demonstrations continued in Eastern Ukraine and more Russian troops moved into Crimea.

“Putin is playing chess and I think we are playing marbles, and I don’t think it’s even close,” Rep. Mike Rogers (R-Mich) said on Fox News Sunday, criticizing the administration’s tepid response to Russia. “They’ve been running circles around us.”