Barack Obama sent strong signals to Vladimir Putin as pro-Russian forces controlling the Crimean peninsula prepare for a vote on when (rather than whether) to annex the province to Russia once again. In a meeting with Ukrainian PM Arseniy Yatsenyuk, Obama rejected the legitimacy of the upcoming plebiscite and warned of “costs” to Russia if Putin pushed forward for his plan to seize Crimea. Yatsenyuk expressed hope that Ukraine and Russia could have a friendly relationship, but pledged that Ukraine would “never surrender”:

U.S. President Barack Obama and Ukrainian interim Prime Minister Arseniy Yatsenyuk had strong words for Russia on Wednesday as Washington again warned Moscow there will be consequences if it doesn’t remove its troops from Crimea and Kiev said that it will “never surrender.”

But Yatsenyuk also said after his meeting with Obama at the White House that Ukraine, a former Soviet Republic, wants to be good friends with Russia.

“We will continue to say to the Russian government that if it continues on the path that is on, then not only us but the international community … will be forced to apply a cost to Russia’s violations of international law,” Obama told reporters. “There is another path available, and we hope that (Russian) President (Vladimir) Putin is willing seize that path.”

Yatsenyuk — who took over after the ouster of Viktor Yanukovych, the pro-Russian former president of Ukraine — said that Ukraine is fighting for its freedom.

“We fight for our sovereignty, and we will never surrender,” he said. Later he added that he wanted to be clear that Ukraine “is and will be a part of the Western world” but still a “good friend and partner of Russia.”

Yatsenyuk isn’t kidding around. Ukraine just voted to mobilize a new National Guard to defend its borders:

Ukraine’s parliament has voted to create a 60,000-strong National Guard to bolster the country’s defences.

The vote came ahead of Sunday’s referendum in Crimea, now controlled by pro-Russian forces, on whether citizens want to join Russia.

President Vladimir Putin insists Russia is not to blame for the crisis.

But Germany’s Angela Merkel says Moscow faces “massive” political and economic damage if it refuses to change course. The US has also threatened action.

That may not be enough, and it might be too late by the time they’re needed:

Russia is gathering thousands of troops, artillery and other equipment at the border with Ukraine as part of military training exercises that are also a blunt reminder the superpower could easily move deeper into the neighboring country.

The exercises are scheduled to take place over the next two weeks amid a standoff with the United States and Europe over the fate of Ukraine’s Crimea region — currently occupied by Russian troops. …

Over the last few days Russian armored vehicles have been spotted in Belgorod, farther to the north. The Defense Ministry said that the exercises included 8,500 artillery troops, along with an assortment of rocket launchers, howitzers, anti-tank guns and other weapons.

Obama noted that Congress is working on aid to Ukraine — but that’s not going very well, thanks in large part to Democrat attempts to use the aid package for their own political goals:

Prospects for quick passage of U.S. financial aid to Ukraine dimmed Tuesday as the Senate’s top negotiator pushed for a broader package that threatens to draw opposition from the Republican-led House.

Senate Foreign Relations Committee Chairman Bob Menendez (D., N.J.) told reporters that he wanted to move the Ukraine aid package Wednesday—including language designed to overhaul and strengthen the International Monetary Fund.

Democrats say the IMF provisions will boost the amount of money the West can loan to Kiev. But many Republicans have balked at the measure, saying it is an attempt by the White House to use a crisis to advance its own agenda.

Last week, the House overwhelmingly voted to provide loan guarantees to Ukraine to fulfill the White House goal of providing $1 billion in short-term aid. Republican leaders believe that measure, which doesn’t include the IMF language, is the only option if Congress is to approve aid this week, when Ukraine’s new prime minister is in Washington.

“It seems very likely that the only way for Congress to act on the issue this week would be for the Senate to pass the House-passed measure,” a House GOP leadership aide said.

Menendez’ committee passed the package with the IMF language in it late yesterday, which means the Senate will need to decide on whether to vote on that bill or the House measure. If Menendez’ version passes, the IMF language could get removed in a conference committee, but that will take some time to go through that process. The quicker route would be to pass the House version, but don’t expect Harry Reid to pass up a chance to stick it to the GOP, even at the expense of the Ukrainians.