(Adds Lavrov comments)
WASHINGTON, June 20 (Reuters) - U.S. President Donald Trump told Ukraine's president on Tuesday that he hoped to see a resolution to the country's crisis but stopped short of publicly endorsing a 2015 accord calling for an end to Kremlin backing for pro-Russian separatist rebels.
Trump sat down in the Oval Office with Ukrainian President Petro Poroshenko for talks that were officially called a drop-by visit after the Ukrainian leader's separate session with Vice President Mike Pence.
With TV cameras rolling, Trump said "a lot of progress has been made" between the two countries and that the two had "very, very good discussions."
In a statement issued after the meeting, the White House said the discussion centered on "support for the peaceful resolution to the conflict in eastern Ukraine and President Poroshenkos reform agenda and anticorruption efforts."
There was no mention in the statement of the Minsk agreement, the 2015 accord aimed at ending Russian support for separatist rebels in eastern Ukraine. Last week, Secretary of State Rex Tillerson said the United States could back away from that agreement to avoid being "handcuffed" by the policy.
However, before Trump's meeting with Poroshenko, the U.S. Treasury announced sanctions on 38 individuals and organizations over Russia's actions in Ukraine, and said the actions were being taken to keep pressure on Russia to reach a diplomatic solution in Ukraine.
Treasury Secretary Steven Mnuchin said in a statement that "there should be no sanctions relief until Russia meets its obligations under the Minsk agreements."
Russian Foreign Minister Sergei Lavrov said the new round of sanctions were regrettable and that "Russophobia" in the United States was raging "beyond all bounds".
The latest sanctions target Ukrainian and Russian officials and companies that U.S. authorities accuse of helping Russia tighten its grip on the Crimean Peninsula, a part of Ukraine annexed by Russia in 2014 in a move Western leaders denounced as illegal.
Poroshenko, speaking to reporters after his session with Trump, said he came away pleased with what he called a "full, detailed meeting." He was also holding talks with Tillerson and Defense Secretary Jim Mattis.
"We received strong support from the U.S. side, support in terms of sovereignty, territorial integrity and the independence of our state," Poroshenko said.
The somewhat neutral body language between Trump and Poroshenko contrasted with chummy photos that emerged from the U.S. president's meeting last month with Russian Foreign Minister Sergei Lavrov and the Russian ambassador to the United States, Sergei Kislyak.
Trump has said he wants better relations with Russia, but his goal has been complicated by tensions between the two countries over Syria and by opposition among many of his fellow Republicans in Congress to warmer ties with Moscow.
On Monday, Russia threatened to shoot down U.S. warplanes over Syria after a U.S. Navy fighter shot down a Syrian warplane.
In a little more than two weeks, Trump is to hold his first meeting as president with Russian President Vladimir Putin on the sidelines of a G20 summit in Hamburg, Germany.
Trump has found himself on the defensive politically over investigations into alleged Russian meddling in the 2016 U.S. presidential election and possible ties between his campaign and Russian officials. Russia denies it has conducted such a campaign, and Trump denies there was any collusion between his campaign and Moscow.
The new sanctions on Russia announced by the Treasury came after the U.S. Senate passed legislation last week that would impose new measures against Russia and limit Trump's ability to roll back sanctions against that country in the future.
Peter Harrell, a sanctions expert at the Center for a New American Security, said he saw the bill, which is now headed to the House of Representatives, as a sign that lawmakers were "skeptical of Trump's intentions toward Russia."
Harrell said he believes Tuesday's actions by the administration were partly intended to ease those concerns and "to send a message to Congress that they do not need to enact new Russia sanctions." (Additional reporting by Alessandra Prentice in Kiev and Maria Kiselyova in Moscow; editing by Caren Bohan, G Crosse and Jonathan Oatis, Ralph Boulton)