WASHINGTON (Reuters) - Legislation reaffirming U.S. support for allies in the Middle East, including a measure to punish Americans who boycott Israel, fell victim on Tuesday to a domestic political dispute that has resulted in a partial federal government shutdown.

The U.S. Capitol is seen as a partial government shutdown continues in Washington, U.S., January 8, 2019. REUTERS/Jim Young

The U.S. Senate voted 56 to 44, falling short of the 60 votes needed to advance the “Strengthening America’s Security in the Middle East Act.”

Most Senate Democrats have vowed to block all legislation in the Senate until it votes on a measure to end the shutdown, criticizing President Donald Trump’s fellow Republicans for backing his demand for $5.7 billion to build a barrier on the border with Mexico before reopening the government.

Republicans increased their Senate majority to 53 to 47 in November’s elections, but they still needed at least seven Democratic “yes” votes for the act to move ahead.

Trump was to give a speech making his case for the wall, a central promise during his 2016 campaign, in a nationally televised speech later on Tuesday.

The Middle East legislation included provisions supported by both Republicans and Democrats to impose new sanctions on Syria and guarantee security assistance to Israel and Jordan. Those are seen as efforts to reassure U.S. allies worried about shifts in U.S. policy since Trump abruptly announced plans last month for a quick withdrawal of the roughly 2,000 U.S. troops in Syria.

U.S. forces in Syria have been fighting against Islamic State militants and also served as a counterweight to the Syrian government, which is backed by Iran and Russia.

However, the act also includes a provision that would let state and local governments punish Americans for boycotting Israel, which opponents, including many Democrats, see as an impingement of free speech.

Some Republicans accused Democrats of supporting the Boycott, Divestment and Sanctions (BDS) movement targeting Israel over its treatment of the Palestinians, which they see as anti-Semitic. Democrats in turn accused Republicans of trying to use the BDS measure to divide moderate and liberal Democrats.

Even if it had passed the Senate, the act would have faced a doubtful future in the House of Representatives, where Democrats now hold a 235- to 199-seat majority, with one seat vacant, after sweeping victories in November.