WARSAW (Reuters) - Poland and the United States denied on Tuesday media reports alleging that the United States had banned high-level meetings with Polish officials in protest over a new law on the Holocaust that has strained Warsaw’s ties with Washington and Israel.

A report published by the privately owned Polish news website onet.pl also said Washington had threatened to block funds for joint U.S.-Polish security measures. Polish officials did not immediately comment on that specific report.

Poland, which has built close security ties with the United States in recent years amid concerns over a more assertive Russia, said “bilateral strategic cooperation” with its NATO ally remained unchanged.

Washington has been very critical of new Polish legislation that makes it a criminal offence to suggest Poland was complicit in the Holocaust, punishable with jail terms of up to three years.

Asked about the report of a U.S. ban on top-level meetings with Polish officials, Deputy Foreign Minister Bartosz Cichocki told TVN24 private broadcaster: “It is not true. There was no ultimatum of that kind.”

U.S. State Department spokeswoman Heather Nauert told a briefing that there were no high-level bilateral meetings planned for now, but that the media reports that allege any kind of suspension in security cooperation or high-level dialogue were “false”.

“That does not mean that we don’t have disagreements about the legislation that has taken effect,” Nauert said.

Onet.pl cited a memo from the Polish embassy in Washington as the source of its report. The Foreign Ministry in Warsaw said it did not comment on media reports regarding classified or official correspondence.

“Bilateral strategic cooperation (with the United States) is not threatened, and diplomatic contacts are maintained at the current level,” the ministry also said in emailed comments sent to Reuters.

It said a deputy foreign minister had visited the United States last week and that another deputy foreign minister would also visit the country soon.

In 2017, Poland welcomed the first U.S. troops in a multi-national force which is being located across the Baltic region to help counter potential threats from Russia. This came after Russia moved nuclear-capable Iskander-M missiles into its Kaliningrad enclave, which borders Poland and Lithuania.

Any hindrance to such security cooperation would alarm Poles who believe Russia wants to expand its influence in the region.

“If it is true, let me repeat, if it is true, then this is a very serious issue, as it may threaten Poland’s security,” state media quoted lawmaker Stanislaw Tyszka as saying on Tuesday.

His anti-establishment grouping Kukiz’15 often cooperates with the ruling nationalist Law and Justice (PiS) party which initiated the Holocaust law.

PiS says the new law is needed to ensure that Poles are recognized as victims, not perpetrators, of Nazi aggression during World War two.

The United States and Israel say the law will curb free speech, criminalize basic historical facts and stop any discussion of the role some Poles played in war crimes.

More than three million of the 3.2 million Jews who lived in pre-war Poland were murdered by the Nazis, accounting for about half of all Jews killed in the Holocaust.

Parliament on Tuesday approved establishing March 24 as a national day for remembrance for Poles who saved Jews during World War Two.

Critics say such a move may be seen as an attempt to re-write history, to show that Poland was solely a nation of victims during the war.